casitas de gila guesthouses bed and breakfast new mexico 575-535-4455
info@casitasdegila.com

Southwestern Guesthouses on 265 Acres
near Silver City, New Mexico
overlooking Bear Creek and the Gila Wilderness

Casitas de Gila Nature Blog

Casitas de Gila Nature Blog

A GLORIOUS HIKE in the Middle Box of the Gila River to a 1,000-year-old Swimming Hole Carved in the Ash-Flow Tuffs of the Schoolhouse Mountain Caldera

 

Burro Mtn. Trailhead Sign

Billings Vista Bird Sanctuary & Trailhead for FT 746

Two week ago, two of our good friends from County Kerry, Ireland, spent a few days with us at Casitas de Gila Guesthouses while touring the American West. At the time, the lightening-caused Whitewater-Baldy fire had been burning for two weeks in the heart of the Gila Wilderness some 20 miles to the northwest of us. Since our guests were avid hikers, and the Forest Service had closed some of our usual hiking trails due to the fire, we decided it was a good opportunity to explore a different part of the Gila National Forest: the Burro Mountains.

The Gila National Forest is huge, offering some 1,500 miles of trails within its 3.3 million acres, and while we have spent a lot of time hiking and exploring the Gila country over the past 13 years, at best we have only scratched the surface, having a tendency to take our various visiting guests to the same favorite areas over and over again.

New Mexico's Burro Mountains in the Gila National Forest

New Mexico's Burro Mountains in the Gila National Forest

Lightening caused fires in the Gila Wilderness are a common occurrence, and during the 13 years that we have lived in Gila we have witnessed several such events. As with previous fires in the Wilderness, the Whitewater-Baldy fire was not affecting the Casitas in any way, either by smoke or other problems, since the Casitas are located south of and, due to prevailing winds, upwind from the Gila Wilderness and the fire. So with prevailing wind in mind, we decided that a good choice for our hike would be the Burro Mountains, about 9 miles south of the Casitas. Most of the Burro Mountains, about 250 square miles or 160,000 acres, lies within the Gila National Forest. It is an interesting and varied mountain range, steeped in history, that is transected by the Gila River at its northern end, and an area which we had only briefly visited a few times before.
 

THE BURRO MOUNTAINS – AN ANCIENT LAND WITH A RICH HISTORY

Geologically, the Burro Mountains display a fascinating and extremely complex history of ancient sedimentary deposition; deep burial; deep seated, magmatic, pluton-forming activity; repeated uplift and erosion; accumulation of thick layers of welded tuff following explosive volcanic caldera eruptions; and extensive faulting, followed by late-stage mineral emplacement. It is a story in stone extending back over 1.5 billion years, where, today, many of the various chapters of this ancient history of the earth are exposed and laid open for all to see in the Middle Box by the eternal downward cutting action of the Gila River over many millions of years.

Silver City, New Mexico's Burro Mountains

Across the Floodplain and into the Woods!

The more recent history of the Middle Box of the Gila is equally as intriguing. In pre-historic times, the entire length of the Gila River was a major thoroughfare for east-west travel, and was considered home to countless generations of early Native Americans such as the Mogollon Culture who hunted, fished, farmed, camped, and built villages both small and large along its course from about 150 to 1400. For the interested and observant hiker, remnant signs of these early cultures can be found in numerous places along the Gila River.

A hundred years or more after the Mogollon peoples left, the Apaches arrived and claimed this dependable desert oasis of the Gila River as home. In the years to come the Burro Mountains were at the center of much of the Apache Wars with the incoming wave of pioneer miners, ranchers, and farmers from the East. During this chaotic period, all the Apache chiefs—Cochise, Mangas Coloradas, Nana, Victorio, Chihuahua, and Geronimo—knew the Middle Box of the Gila River intimately.

Cottonwood trees in Burro Mountains

In the Hall of the Cottonwoods

With the gradual taming of the West, it was inevitable that the ubiquitous and intrepid group of men known as prospectors would find their way into the Burro Mountains. And, much to their great joy and delight, here they found silver and yellow metals in great abundance. Beginning in the 1880s, and fully established by the early 1900s, several mining districts were recognized at various places within the Burro Mountain chain. Scattered throughout these rugged mountains and canyons numerous small prospects and mines were developed, yielding significant amounts of gold, silver, copper, turquoise, and fluorite1,2. Within a few decades, however, all but a few of these small mining operations had been worked out and had ceased production. But, then, just as the small mines began to close, intensive mineral exploration projects were undertaken in the southern Burro Mountains which eventually delineated the presence of extensive and massive deposits of low-grade copper ore which could be extracted at a profit, if done on a large scale. Thus was born a new phase of mining in the Burro Mountains. It is one that continues today in the form of the mega-scale operation of Freeport-McMoRan Copper and Gold Corporation’s Tyrone Mine, located in the southern Burro Mountains, about 15 miles south of Silver City. The Tyrone Mine is a huge open pit and processing facility which in 2010 produced 37.19 thousand tons of copper3.

In the northern Burros, however, most of the old mines, prospects, and workings ceased operations long ago and are now mostly forgotten and inaccessible, scattered throughout a rugged and roadless terrain.
 

THE MIDDLE BOX OF THE GILA RIVER AND FOREST TRAIL 746

Gila National Forest Hiking Trail

Off We Go!

And so it, was with a sense of heightened anticipation on my part for a trail never travelled, that our two guests, two neighbor friends, two dogs, and myself set off for a day hiking and exploring Forest Trail 746 in the Middle Box of the Gila River.

In New Mexico, the term “box” is used to describe the narrow canyons along the course of a river or creek, which can serve as a handy place for ranchers to drive and corral or “box” up their wide-ranging cattle. In the case of the Middle Box, it refers to the narrow canyon cut by the Gila River as it transects the north-south trending Burro Mountain Range between the Upper Box at the edge of the Gila Wilderness upstream and the Lower Box of the Gila near the Arizona border downstream.

Swimming Hole in Gila River near Silver City, NM

The Swimming Hole of the Ancients

Forest Trail 746 is a well-marked trail which leads downstream, deep into the high-walled canyon narrows of the Middle Box of the Gila River. Recently the trail has been upgraded for at least the first two miles. Substantial rock cairns mark the way across the wider stretches of sand and gravel floodplain that are devoid of vegetation, and the trail has been cleared as it goes through the dense stands of young cottonwood, willow, and shrubby vegetation that border the river channel. The trail follows the east side of the river for the first 0.7 mile, and then crosses to the west side of the river for the remaining 1.3 miles to the destination and end point of this trail discussion, the Swimming Hole of the Ancients.

Prickly Poppies in New Mexico

The Prickly Poppy (Argemone pleiacantha) abounds along FT 746

Trail 746 is a trail that can be enjoyed by people of every age and ability. The first two miles the trail are mostly across level floodplain with only a few gentle grades. The trail meanders back and forth, towards and away from the river, first across sunlit expanses of river sand and gravel, and then beneath shady canopies of thick stands of young, 80- to 100-foot-tall Fremont Cottonwoods (Populus fremontii) that germinated along the natural levees of former floodplain channels.

In many ways, FT 746 is a passage of riverine solitude for the senses and one’s soul, offering an unforgettable, tranquil, and calming journey into the subtle essence of Gila River country. The weather on the day of our excursion was typical for the first week of June: sunny and in the mid-80s with clear blue skies and a nice breeze out of the south blowing upstream. At this late-spring time of the year, the floodplain vegetation along the river was already in full summer dress, a ribbon of green having diverse fragrant smells, and many flowers, such as Prickly Poppy (Argemone pleiacantha), lining the trail. Although the Spring bird migration had peaked a few weeks earlier, the varied calls of numerous transient species could be heard frequently, rising melodically over the ceaseless background murmur of the cottonwood leaves rustling in the canopy high above. Indeed, it was a glorious morning, and we were all reveling in it, including Red and Bower, our two canine companions.

Gila River in Burro Mtns in New Mexico

Huge, old cottonwood washed out at river crossing

FT 746 begins by first crossing a dissected outwash plain of sand, gravel and boulders washed out from Ira Canyon to the east. It then rises briefly to cross a stretch of older river terrace of sand and gravel, densely covered with Honey Mesquite (Prosopis glandulosa) and a few One-seeded Juniper (Juniperus monosperma), before dropping down to the upper part of a broad modern floodplain sparsely covered with Rubber Rabbitbrush (Ericameria nauseosa), Seepwillow (Baccaris salicifolia) and the occasional old-growth cottonwood. After 0.2 mile, the floodplain narrows and the trail passes into a dense stand of mature cottonwood and willow which continues for another 0.2 miles. After passing through a particularly dense stand of trees, the trail then emerges abruptly at a broad, shallow river crossing. The crossing point is well marked by the remains of a huge, old growth cottonwood that toppled into creek in recent years when the river bank was undercut during a period of flooding and the eastward lateral migration of the main channel. As typical for this time of year, the flow of the Gila was low, only about calf-deep, when we made the crossing. The Spring runoff, minimal as it was this year because of a second-year-in-a-row dry La Niña Winter, had peaked several weeks earlier.

Burro Mountains in Gila National Forest New Mexico

Once the river was crossed, the trail again entered into a zone of alternating stretches of floodplain sand and gravels, and dense, high-vaulted stands of young cottonwood and willow, with an understory of waist-high, thick-growth young willow trees.

The contrast in sensual perception between the alternating sunlit, barren sand and gravel, and shaded, lush vegetated tunnels of plant growth was intense and inescapable as we hiked the next half mile of the trail. Leaving the floodplain, we followed the trail as it climbed up onto the bordering mesquite and juniper covered terrace, and then abruptly emerged at the top of a 15- to 20-foot-high, white rocky promontory jutting out into the river. We had arrived at our lunch time destination, the Swimming Hole of the Ancients!

Burro Mountains Gila National Forest New Mexico

Our lunch spot, overlooking the Gila River

And what an idyllic and magical spot it is! Within less than a minute, our canine buddies were frolicking in the river, swimming, and chasing sticks, while their owners and friends relaxed at the promontory’s edge and examined the intriguing grinding holes made a thousand or more years ago by the ancient tribes that passed this way. There could be no doubt that the ancients considered this place as special as we did. The 4 to 6 inch depth of the several holes at the top of the rock promontory where they ground their maize and other food stuffs offer mute testimony that countless generations of ancient travelers had paused here to swim, rest, and eat before or after passing through the rugged, narrow, rocky chasm of the heart of the Middle Box that our map indicated was just another half mile or so downstream.

Mimbreno grinding hole in Burro Mtns in New Mexico

Where the Ancients ground their maize

This rocky promontory is the first outcrop of bedrock to be found within the river as one hikes downstream towards the narrows of the Middle Box, a telltale sign of the chasm ahead. The ancients, of course, knew this, and also knew that this rock was excellent for grinding grain, although they didn’t know why. It would be a thousand years or more before geologists would come to understand the why, that this abrasive rock is a rhyolite ash flow welded tuff, deposited there some 33.5 million years ago in the Late Oligocene Epoch during an eruption of the Schoolhouse Mountain Caldera, about 3 miles to the east (Ref. 1).

Gila National Forest New Mexico

Time for Lunch!

Sitting there quietly munching a sandwich and observing our surroundings as the afternoon breeze rushed upstream through the leaves of the thick stands of willow and cottonwood lining the banks, it was not at all surprising when the vision of how it must have been began to play in one’s mind … a scene of young children playing, swimming, and jumping from the promontory into the river below, under the ever-watchful eyes of their mothers grinding the corn on the rocky promontory above, while the older men scoured the mesquite thickets on the hillside behind for a nice plump rabbit to round out the meal.

And then, all too soon the scene faded, and we knew it was time to pack up and head back.

 

DIRECTIONS FOR FINDING FOREST TRAIL 746

Sign for FT 746

Trailhead Sign for FT 746 in the Burro Mountains

To reach the trailhead for Forest Trail 746 from Casitas de Gila Guesthouses, take NM 211 south from the Gila Post Office for 4 miles to US 180; turn right (west), and in 1 mile turn left on Bill Evans Lake Road. At 3.4 miles the road forks, with the road to the left leading away from the river to Bill Evans Lake. At this fork stay straight ahead for 1.9 miles to enter the Gila National Forest. After going another 4.5 miles the road leads to a designated and marked birding area with access to the Gila River. At this point continue driving south, parallel to the river, on a less travelled dirt road to dead end at the Billings Vista Birding Area and the trailhead for Forest Trail 746.
 


REFERENCES:

  1. 2005, Virginia T. McLemore, Mineral Resources of the Wild Horse Mesa Area, Northeastern Burro Mountains, Grant County, Open-file Report 486.
  2. 1964, Elliot Gillerman, Mineral Deposits of Western Grant County, New Mexico, New Mexico Bureau of Mines and Mineral Resources, Bulletin 83.
  3. Mining Almanac


 

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Milky Way Rising • April New Moon

The skies were dark during the April 2012 New Moon period, the Casitas were full of amateur astronomers, and the weather was wonderfully dry and clear!

We know from talking with our guests at Casitas de Gila Guesthouses that there are quite a few who have never seen the Milky Way because of the amount of light where they live. Right now the Milky Way is rising out of the southern sky in the very early morning hours. Alarm clocks are being set for 3 AM and guests are getting up to observe all of its magnificence.

Here are some photos taken by one of our April New Moon guests. Fritz Kleinhans is an amateur astrophotographer/astronomer and retired physics professor. This was his third visit to the Casitas and he is delighted to share these photos with our Casita guests past, present, and future. He’ll be back next spring, taking more photos and viewing more deep-sky objects.

Click on each picture to view a larger version.

The Spring Milky Way

The Milky Way
(4 minute exposure with a Canon 15mm F2.8 fisheye lens)

M81 and M82 deep sky objects

Deep Sky Objects
M82 (Cigar Galaxy) and M81 (Bode's Galaxy)
4 subframes, 10 minutes each, 40 minutes total exposure; two dark and one flat frame; ISO 800 with extended red filter

astrophotography telescope

The scenery during the day time at Casitas de Gila is just as spectacular as the night skies!

astrophotography telescope

Fritz uses a Hutech modified Canon 400D camera on a TEC 140mm apo refractor, fl=980mm, f7; Astro Tech Field Flattener with an Astro Physics Mach 1 Goto Mount

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The Catwalk and Gold Dust Trails in Southwest New Mexico

A SPECTACULAR JOURNEY INTO THE 34-MILLION-YEAR-OLD
MOGOLLON SUPERVOLCANO OF THE GILA WILDERNESS

With his long-awaited discharge from the U.S. Army at Ft. Bayard in 1875, Sergeant James C. Cooney was at last free to pursue the exploration and development of a mineral vein he had discovered and claimed five years earlier while on patrol up what is now known as Mineral Creek in Catron County, about eight miles northeast of the present community of Glenwood, New Mexico. Within a short time, the claim proved to have valuable tonnage of copper, silver and gold ore. As news of the success of Cooney Mine’s spread, the small mining enclave of Cooney Camp swelled to a population of some 300 to 400 souls as mine workers and prospectors descended on the area. Encouraged by the results of his mine, Sgt. Cooney organized a group of interested partners to prospect the surrounding mountains. The subsequent history of Cooney Camp, and how the veins of that area were traced a couple of miles southward into what was to become the famous Mogollon Mining District, is one of the most fascinating chapters of New Mexico’s early mining history.

One of Sgt. Cooney’s partners was a man by the name of John Lambert1, of whom little is known other than the fact that he apparently was quite successful in locating rich veins of gold and silver in the mountains about a mile east of the soon-to-be boom town of Mogollon. By the 1890s, Mogollon was bursting at the seams with some 3,000 to 6,000 miners and associated supporting humanity, and the rich veins that Lambert found had been developed into the Confidence, Bluebird, Blackbird, and Redbird mines. Of these, the Confidence Mine proved to be especially rich Over the years it was mined to a depth of some 1,030 feet, with production reported to have yielded about $1,200,000, a princely sum in those early days in frontier New Mexico2.

The Original Catwalk

John T. Graham was the Superintendent of the Confidence Mine during its early years and quickly saw that the economics of the mine would be greatly enhanced if a processing mill could be developed nearby. He knew that short transportation distances and an ample supply of year-round water would be the critical factors in establishing such a mill. Since the mines surrounding the Confidence Mine were all within a mile or less of the only route connecting Mogollon with the San Francisco River valley to the west (now called the Bursum Road or State Road 159), Supt. Graham hit upon the idea of building a mill on the northwest slope of Whitewater Creek Canyon, about two miles south of the mines, and just downstream from where Whitewater Creek exits the extremely narrow and steep-walled canyon now known as the Catwalk Recreation Area. This site was ideal, he reasoned, since it was only three or four downhill miles from the mines via the Bursum Road route to the south edge of Whitewater Mesa, where the ore could then be easily delivered to the mill a few hundred feet below through an ore chute. The critical factor of water supply could be satisfied by building a pipe line up the narrow slot canyon of Whitewater Creek.

With the help and partnership of ex-Colorado Governor David Moffat, the envisioned mill was completed in 1893, with an initial water supply provided by a four-inch pipeline which was laid up Whitewater Canyon. In honor of its founder, the new mill was named the Graham Mill, and the small town of some 200 people that grew up around the mill was also named Graham, although some preferred the alternate name of Whitewater. The exact site of the town is now the parking area for the Catwalk Recreation Area. Within a short time the water demands of the mill and the town exceeded what the 4-inch line could provide, and a new 18-inch pipeline was built up the canyon on a wood and steel framework sometimes elevated as much as 20 feet above the creek. In the narrowest part of the canyon, square holes were chiseled in the sheer volcanic rock walls to hold the timbers and wooden walkway supporting the heavy pipe. All in all, the pipeline and supporting framework was an incredible engineering feat. Mill records reveal that because of frequently-occurring floods, this large iron pipeline required constant maintenance. Workmen assigned to keep the pipeline functioning were required to hike up and down the pipeline on a wooden planked platform running beside the pipeline, which they quickly came to call “the catwalk”.

Graham Mill

Graham Mill

The Graham Mill was a substantial structure, and essentially state of the art for the times. The mill was powered by a Pelton water wheel capable of producing 350 HP, backed up by a wood-fired, 300 HP Corliss steam engine during periods of low water, and boasted a purported processing capability of up to 75 tons of ore a day. However, despite several upgrades, the mill never achieved its full potential and eventually ceased operations permanently in 19133. In time, as was the case with so many of these short-lived mining towns in the Southwest, all of the buildings and machinery were dismantled, sold, and moved away. Today, the only remains of the mill and town of Graham are a few decaying timbers and rock-terraced foundations of the mill which can be seen on the side of the canyon on the southwest side of the Catwalk parking area.

Remainder of Graham Mill

Ruins of Graham Mill

From 1913 until 1934 the deep rocky chasm of Whitewater Canyon and the Catwalk was largely forgotten and silent except for the sounds of rushing water and wind. Then, in 1935, the Civilian Conservation Corps, or CCC Boys as they were called in those days, were given the task of rebuilding the Catwalk and the lower portion of Whitewater Canyon as a recreation area as part of the Gila National Forest. The project took two years and served until 1961, when the old wooden Catwalk was replaced by the Forest Service with a new metal catwalk. In 1978, the Catwalk portion of Forest Trail 207, plus an additional 1.15 miles of the trail to the junction of Whitewater Creek and South Fork, were designated a National Recreation Trail. Since then, the Catwalk and the adjoining trail system have been repeatedly upgraded and expanded over time, most recently in 2003, with the $1.5 million installation of a new steel catwalk, plus the construction of a new half-mile wheelchair-friendly trail on the southeast side of the lower portion of the Catwalk. Today, some 325 miles of interlocking trails in the high country of the Mogollon Range can be accessed where Forest Trail 207 and Forest Trail 41, the Gold Dust Trail, split off from the Catwalk Trail at the west end of the suspension bridge near the 1.0 mile marker of the Catwalk.

The Catwalk Trail and Recreation Area is a true national treasure for the outdoor enthusiast. No matter what your passion — seeking out the cultural history of the Old West, pursuing photography or painting, quiet contemplation within the inspiring beauty of pristine Nature, seeing and learning about the unique and spectacular volcanic geology of the Gila Wilderness, enjoying a refreshing soak and swim in the crystal clear waters of Whitewater Creek at the end of a High Country Hike on a hot Summer day — there is great joy to be had at the Catwalk regardless of age or physical abilities. Indeed, it is extremely rare to find as much diverse natural beauty and opportunities for outdoor pursuits packed into such a short section of trail as can be experienced on the 1.25 mile long journey along the Catwalk Trail.

Regardless of one’s skill level, technique, or interest, the Catwalk offers the nature photographer or artist easy and unique access to endlessly-inspiring subject matter throughout the year. At virtually every step along the trail one encounters an ever-changing drama of light and shadow as brilliant rays of sunlight alternately penetrate, illuminate, refract, reflect, and suddenly extinguish amongst the sheer canyon walls, the twisted trunks and branches of the ancient cottonwood and sycamore, and the churning, tumultuous waters of boulder-strewn Whitewater Creek.

For many of us, simply to experience the overpowering natural beauty of the Catwalk is more than enough reward for a day spent in the enchanting world of Whitewater Canyon. However, at some point, some visitors may begin to have questions regarding the underlying causes and processes that have created the unique and special character of the Catwalk Trail that we have come to enjoy. It is in anticipation of those questions that a short discussion of the underlying geology is herein presented; an understanding, which, hopefully, will lead one to an even deeper and richer appreciation of what a truly special place the Catwalk is.

 
THE MOGOLLON SUPERVOLCANO

The Casitas de Gila Nature Blog of March 2011, The Supervolcanoes of the Gila Wilderness, presented a geologic overview concerning two periods of major and highly explosive volcanic activity that occurred within the Mogollon Range in the western half of the Gila Wilderness when the proposed Mogollon, Bursum, and Gila Cliff Dwelling super-volcanoes erupted some 34 and 28 million years ago. Extensive geologic field research conducted over the past 30 years in the Mogollon Range east of Glenwood, New Mexico (specifically within the Mogollon and Holt Mountain4 quadrangles) reveals a complex history of periodic repeated vulcanism. The sequence of events starts with an initial filling and swelling of a deep seated magma chamber, followed by explosive eruption and then subsequent collapse of the overlying caldera. Not much is known about the size and extent of the actual caldera of the 34-million-year-old Mogollon Supervolcano (proposed in 2006 by James Ratté, a geologist with the United States Geological Survey), since all but a small exposure of its presumed location is covered over by younger thick volcanic deposits from the 28 million year old Bursum and Gila Cliff Dwellings supervolcanoes. But even though the caldera of the Mogollon Supervolcano itself is deeply buried, geologists have been able to discover and document much about the nature and volcanic history of this ancient supervolcano by studying the extensive 2,500- to 3,000-foot-thick sequence of volcanic deposits that were ejected from the caldera and are now beautifully exposed along the Catwalk and Gold Dust trails of Whitewater Creek Canyon, and in Mineral Creek Canyon to the north.

The thick layered deposits of volcanic material from the Mogollon Supervolcano now exposed along the Catwalk Trail are collectively called the Cooney Tuff formation, which consists primarily of various types of welded ash fall and ash flow tuffs, or ignimbrites, as they are sometimes called. Welded tuffs are composed of fine to microscopic volcanic mineral matter and rock particles which are explosively ejected into the atmosphere during a volcanic eruption in the form of an incandescent, super-dense gaseous cloud which then settles back to earth still in a near-molten state, where the particles fuse or weld together to form layers of rock. The name Cooney Tuff comes from the extensive exposures of these rocks where they were first described and mapped around the old gold, silver and copper mining district of Cooney Camp, which was discovered in the late 1800s in Mineral Creek Canyon, about four miles north of Whitewater Canyon (see Casitas de Gila Nature Blog on Mineral Creek). Today, as a result of extensive study and mapping done by Ratté and others, the rocks of the Cooney Tuff formation have been divided into three distinctly different rock type units, or Members as they are called in geological terminology, which can be traced throughout the area. From oldest to youngest, these are: 1) the South Fork Member of the Cooney Tuff; 2) the Whitewater Creek Member of the Cooney Tuff; and 3) the Cooney Canyon Member of the Cooney Tuff. Together these three members of the Cooney Tuff formation comprise all of the colorful rocks that make up the canyon walls observed along the Catwalk and Gold Dust trails.

 
A GEOLOGIC TRAIL GUIDE TO THE CATWALK AND GOLD DUST TRAILS

The following brief geologic trail guide is based on the geology observed along the original Catwalk Trail which begins on the west side of Whitewater Creek immediately after leaving the parking area; the Gold Dust Trail (Forest Trail 41) which leaves the Catwalk Trail at the 1.0 mile marker; and an alternate return route from a trip up the Catwalk Trail that takes one over the new wheelchair-friendly trail on the southeast side of Whitewater Canyon. Descriptions for the Catwalk portion of the guide are keyed to the 6-inch diameter iron pipe trail markers which the Forest Service has placed at ¼ mile intervals along the trail.

Cooney Canyon Member Tuff

Cooney Canyon Member Tuff with larger rock fragments blasted from caldera wall

Just past the picnic area, the first rock outcrops encountered are light grey to reddish tan welded tuffs belonging to the Cooney Canyon Member of the Cooney Tuff. Here the rocks are highly fractured, brecciated, and in some places pulverized due to the presence of a major north-south trending fault system which separates the San Francisco River Valley on the west, behind you, from the uplifted front of the Mogollon Mountain Range to the east, which you are now entering. Cooney Canyon Member rocks range in composition from rhyolite to dacite. If you look closely at these rocks, you will see larger chunks of angular rock fragments that are imbedded in the matrix of the finer, welded ash tuffs which were blasted from the volcano in an explosive eruption before falling back to earth. If you look very closely, you will also find numerous joints or fractures in the rock where the rock surfaces on either side of the fracture appear to be polished and may exhibit parallel striations or grooves on the polished surfaces. These features are called slickensides and are evidence of frictional movement or micro-faulting along these breaks in the rock.

Slickensides

Slickensides in Cooney Canyon Member

Continuing on up the trail, a little beyond the ¼ mile marker, you come to a sheer cliff rising before you which is composed of a very different looking rock than the exposures of the Cooney Canyon Member that you have been passing through. This cliff face, along with the abrupt change in rock type, marks the presence of another major northwest trending, almost vertical fault, named the Catwalk Fault. Here the rocks composing the cliff on the east side of the fault in front of you belong to the Whitewater Creek Member of the Cooney Tuff, and have been moved up relative to the rocks of the Cooney Member on the west side of the fault, which have been moved down.

Lithophysae

Lithophysae in White Water Creek Member

Crossing the fault and examining the rocks of the Whitewater Canyon Member, you will immediately notice that this rock is characterized by the presence of abundant, irregularly shaped globular cavities in a massive, strongly fine-grained salmon or pinkish-red color welded tuff. The rocks which comprise the Whitewater Canyon Member are rhyolite in composition, which, by definition means that the rock is very rich in silica. Verification of this classification can be readily ascertained by looking closely at the rock where small phenocrysts of quartz will be seen imbedded in the finer matrix material. Also, if you look closely at the globular cavities, you will see that many of them are lined with very small quartz crystals. These unusual features are called lithophysae, which literally translated from the Latin means “stone bubbles”, which gives a good clue to their origin. Lithophysae are formed by bubbles of gas expanding within incandescent ash fall and ash flow tuff deposits as they accumulate, compact and solidify.

The Narrows of the Catwalk

The Narrows of the Catwalk, cut in massive rhyolite welded tuff of the Whitewater Creek member, showing square holes cut in canyon wall to hold original support timbers for the Catwalk pipeline

The Whitewater Canyon Member comprises the full length of the narrow, slot canyon portion of the Catwalk Trail providing today’s visitor to the canyon with unlimited opportunity for close-up examination of this unusual rock type from the new steel walkway secured to the vertical canyon walls some 20 feet above the creek. At numerous places along the walkway one can also observe the square holes that workmen from the Graham Mill chisled into the canyon walls a hundred years ago to secure the massive timbers required to support the heavy iron water pipe coming down from the upper reaches of White Water creek.

Soon after passing the ½ mile trail marker and just after crossing the wooden bridge, the narrow slot canyon is abruptly left behind as the trail begins a steady climb up a much wider canyon composed once again of welded tuffs belonging to the Cooney Canyon Member. What has happened here is that another major fault has been crossed, which, with a little observation, can be seen exposed on both sides of the canyon. If one pauses for a moment at this point and reflects on the sequence of rock units that one has passed through in the first half-mile journey up the Catwalk trail, there is an interesting chapter in the geologic history and evolution of the Catwalk Trail that is waiting to be revealed here.

 
A HORST IN THE CATWALK TRAIL

At the beginning of the Catwalk Trail, the rocks were identified as belonging to the Cooney Canyon Member, the youngest and upper-most member of the Cooney Tuff formation. Then, just before the canyon abruptly narrows to a sheer-walled slot canyon, the Catwalk Fault was crossed and immediately the composition of the canyon walls changed into the massive, dense and lithophysae-bearing rhyolite welded tuff of the Whitewater Member, which as the middle member of the three identified members of Cooney Tuff formation, makes it older, and hence deposited before, the rocks of the Cooney Canyon Member. Finally, just beyond the half-mile trail marker, another major fault was crossed just as the canyon abruptly widened significantly and once more the rocks were identified as belonging to the Cooney Canyon Member.

Catwalk geology

Vertical fault on east side of the Whitewater Creek Member Horst Block. Reddish-tan rhyolite welded tuff of Whitewater Creek Member on left side of fault; white welded tuff of Cooney Canyon Member on right side of fault.

Pondering the origin of this sequence of rock relationships, one eventually comes to realize that the only possible explanation for this sequence is that the massive block of the older White Water Creek Member of the Cooney Tuff formation, which is bounded on each side first by faults and then by rocks of the younger Cooney Canyon Member, has to have been moved up or uplifted, relative to the younger Cooney Canyon rocks, which have been moved or dropped down on each side of the White Water Creek Member block. In geological terms, this type of structural feature is called a horst. The significance of this structural feature to our discussion of the Catwalk geology is that an understanding of the sequence of events leading up to and after the uplift of the horst block of the Whitewater Creek Member is key to understanding how the sheer-walled slot canyon portion of the Catwalk came to be formed. The following interpretation for the origin of the slot canyon offers one possibility.

 
THE CREATION OF THE NARROWS OF THE CATWALK TRAIL

Originally, during the period of time when the Mogollon Supervolcano was active, and long before faulting uplifted the horst block of the Whitewater Creek Member, the area where the Catwalk Trail is now located was covered with thick, widespread deposits of what we now call the Whitewater Creek Member rhyolite welded tuffs. As repeated eruptions of the Mogollon Supervolcano continued, these rhyolite tuffs were, in turn, covered over with subsequent deposits of Cooney Canyon Member welded tuffs. With the end of the Mogollon Supervolcano eruptions, around 35 million years ago, this part of the Gila Wilderness remained relatively quiet for some 5-6 million years. After this period of quiescence, volcanic activity once more resumed in the area with an extended period of repeated explosive eruptions of the Bursum Supervolcano, centered a short distance to the east, which deposited thick layers of volcanic material on top of the Cooney Canyon Member welded tuffs. Following the end of the Bursum Supervolcano eruptions, about 28 million years ago, the area was quiet once more and an extended period of erosion commenced over the area. It was during this time that an ancestral Whitewater Creek began to cut down through the thick layers of volcanic tuffs where the Catwalk is today.

Eventually, after several more millions of years of erosion, the ancestral Whitewater Creek had succeeded in cutting a deep canyon through the Bursum Supevolcano deposits and down into the underlying Cooney Canyon Member deposits. It was at this point, perhaps around 17 million years ago, that a period of extensive faulting occurred, which was probably related to the collapse of the Bursum Caldera. With this faulting came the uplifting of the Whitewater Creek Member horst block. And, as this block was moved upwards, the ancestral Whitewater Creek, which by now was confined to a deep canyon cut in the Cooney Canyon Member deposits, accelerated its downcutting through Cooney Canyon deposits and began cutting into the underlying and uplifted Whitewater Creek Member horst block. Because of the greater density and hardness of the Whitewater Creek rhyolite welded tuff deposits, the ancestral Whitewater Creek soon became captive or entrenched in a narrow, sluice-like channel cut into the rock from which it could not escape. The physical process controlling this type of stream erosion is that when the hydraulic energy of a stream is confined to a narrow channel in resistant rock, the result is intensified downward cutting action, as opposed to what happens to a stream cutting into softer materials, where the hydraulic energy of the moving water is dispersed over a broader area as the banks bordering the stream are eroded away through greater lateral cutting action. Thus it was, after millions of years of such continued entrenched downcutting, that the Whitewater Creek Narrows of the Catwalk Trail eventually evolved into the spectacular chasm that one sees today.

 
THE UPPER HALF OF THE CATWALK TRAIL

sandstone breccia beds

Coarse-grained volcaniclastic sandstone breccia beds in Cooney Canyon Member

After crossing the wooden bridge just past the 1/2 mile marker, the Narrows are left behind and the canyon, widens offering impressive views from the trail. From here to the end of the Catwalk Trail at the 1-1/4 mile marker the rocks observed along both sides of the trail and the colorful towering canyon walls above belong to the Cooney Canyon Member. As was described at the beginning of the Catwalk Trail ,this upper member of the Cooney Tuff formation consists primarily of thick sequences of fine-grained, light grey to reddish tan welded ash-fall and ash-flow welded tuffs of rhyolite to dacite composition. At various places along this section of the trail, however, the observant traveller will come across or notice in the canyon walls overhead a number of thin interbedded layers of a dark brown to almost black, fine- to coarsely-grained rock, which are strikingly different in appearance and texture from the dominant fine-grained light-colored welded tuffs of the Cooney Canyon Member. These dark-colored rocks, which have been variously described by Ratté and others as volcaniclastic sandstones or sandstone breccias, remain somewhat of an enigma as to their origin. In some places, these thin beds display fluvial cross-bedding and graded bedding on the outcrop, which would suggest deposition by running water. However, when examined in thin-section under the microscope, some samples are found to contain delicate shards and bubbles of volcanic glass, which would be more indicative of volcanic fallout from the atmosphere. It is clear that more research is required before the true origin of this unusual rock is understood.

Catwalk Nature Trail

Steel steps leading down over Cooney Canyon Member outcrops to the waterfall and swimming hold on Whitewater Creek

Cooney Canyon Member welded tuff

Cliff of Cooney Canyon Member welded tuff with interbedded layers of dark-colored, volcaniclastic sandstone



Cooney Canyon Member welded tuff

Closeup of Cooney Canyon Member welded tuff with abundant rock fragments

Just before reaching the 3/4 mile marker, a good example of the cross-bedding in the volcaniclastic sandstone can be found, with only a little searching, on a rock outcrop right at the side of the trail, immediately opposite where a steep metal stairway departs from the main trail to descend to a scenic waterfall and swimming hole below in Whitewater Creek. Further along, near the 1 mile marker, several more of these dark interbedded volcaniclastic sandstone beds can be observed high up on the north facing canyon walls. Then, soon after crossing a short suspension bridge, the Catwalk Trail ends at the 1.1 mile marker in a recessed rock alcove in the canyon wall. Here, acting over thousands of years, the rushing waters of Whitewater Creek have cut deeply into one of the volcaniclastic sandstone layers, affording ample opportunity for close-up study of this unusual and enigmatic rock type.

Catwalk Trail

The alcove at the end of the Catwlak Trail cut into volcaniclastic sandstone

Catwalk Trail

The alcove at the end of the Catwalk Trail taken from the Gold Dust Trail



volcaniclastic sandstone layers

Closeup of volcaniclastic sandstone layers in the alcove

 
THE HIGH COUNTRY VISTAS OF THE GOLD DUST TRAIL

Suspension Bridge at Catwalk

West end of suspension bridge on the Catwalk Trail showing junction of Gold Dust Trail (Forest Trail 41) and Forest Trail 207

The Catwalk Trail offers an unequaled and probably the most accessible opportunity for a close-up examination of a thick sequence of some of the dominant volcanic rock types that are found throughout the western half of the Gila Wilderness. For those visitors who would like to put this understanding into a somewhat broader perspective by looking at the various rock units from a greater distance, such an opportunity is close at hand. To gain this perspective it is only necessary to retrace one’s steps back from the alcove to the 1 mile marker at the beginning of the suspension bridge where Forest Trail 41, the Gold Dust Trail, begins an easy 1-1/4 mile climb out of Whitewater Canyon to Whitewater Mesa some 500 feet above.

The Gold Dust Trail offers incredible views to the east up Whitewater Canyon to the High Country of the northern Mogollon Range, and down the Canyon to the west past the Catwalk parking area to the San Franciso River Valley and the Blue Range Wilderness beyond. All but the western-most end of the Gold Dust Trail passes up through and over layers of the Cooney Canyon Member of the Cooney Tuff, providing close up examination of the rocks within the upper deposits of the member which could not be observed from the Catwalk Trail. Between 1/2 and 1 mile up the Gold Dust Trail excellent views of the entire southeast side of the Catwalk Canyon are possible that clearly show numerous faults and other structural relationships between the three members of the Cooney Tuff formation.

Whitewater Canyon New Mexico

Looking east up Whitewater Canyon from the Gold Dust Trail

  
Whitewater Canyon New Mexico

Looking west down Whitewater Canyon from the Gold Dust Trail across Whitewater Mesa, the San Francisco River Valley and into the Blue Range Wilderness Area



 
EXPOSURES OF THE LOWER SOUTH FORK MEMBER OF THE COONEY TUFF ALONG THE NEW TRAIL ON THE SOUTHEAST SIDE OF WHITEWATER CREEK

To complete one’s geological investigation of the Cooney Tuff at the Catwalk, an alternative route for one’s return trip down the Catwalk Trail is to take the new trail along the southeast side of the canyon where excellent exposures of the South Fork Member, the lowest member of the Cooney Tuff formation, are exposed.

Leaving the old trail at the western end of the suspended metal catwalk in the Narrows, the new trail crosses Whitewater Creek and almost immediately enters a highly brecciated fault zone. Because of the extreme shattering and overall weakness of the rock encountered within this fault zone during the construction of the new trail, it was necessary to drill and install numerous rock bolts to secure the unstable cliff face. Once past the rock-bolted area, exposures of two different rock types typical of the South Fork Member are well exposed on the cliff face next to the trail. These consist of a thin, dark-colored mafic lava flow, which is overlain by a thicker layer of light-colored welded tuff.

In contrast to the other two members of the Cooney Tuff formation, the South Fork member contains several, dark-colored, mafic or basaltic (iron and magnesium rich, and silica poor) lava flows and related mafic pyroclastic rock units, which are interbedded with light colored, felsic welded tuffs similar to the rock types seen in the Cooney Canyon Member along the Catwalk Trail. These mafic lava flows are unique within the Cooney Tuff formation and represent the only evidence reported to date of molten lava flows emanating from the Mogollon Caldera.

Continuing past these last rock outcrops, the trail soon enters an extensive zone of Quaternary landslide deposits before reaching the Picnic Area and the end of the geologic guide to the Catwalk and Gold Dust Trails.

 
REFERENCES

  1. 2000, The Catwalk of Whitewater Canyon U.S.F.S. Brochure available (.pdf file).
  2. 1927, Henry G. Ferguson, Geology and Ore Deposits of the Mogollon Mining District, New Mexico, U.S. Geological Survey Bulletin 787 (.pdf file).
  3. 2008, James C. Ratté, Geology Along the Catwalk National Recreation Trail Near Glenwood, New Mexico, in Geology of the Gila Wilderness-Silver City Area, New Mexico Geological Society Guidebook, 59th Field Conference, p. 16-26.
  4. 2006, Ratté, Jim, Lynch, Scott, and McIntosh, Preliminary Geologic Map of the Holt Mountain Quadrangle, Catron County, New Mexico, New Mexico Bureau of Geology and Mineral Resources, Open-file Digital Geologic Map OF-GM 120

 

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The Subtle Signs of a Southwest New Mexico Spring

While Michael is busily researching his next blog, which will be on the Catwalk Nature Trail, I want to share with you some of the very subtle growth that tells us Spring has arrived. Spring in Southwest New Mexico does not last long. Right now our daytime temperatures are in the 70s and overnight the temps drop to the high 30s and low 40s. When we take ourselves and our dogs out for our 7 AM walk every day, we are still bundled up in winter coats, scarves, hats and gloves! But by mid-day, it’s sandals and lightweight shirts!

We have had a little bit of rain (and snow) over the past three months — less than an inch. But it has been enough for some of the southwestern deserts plants to bloom. We took these photos at 7 AM this morning, when the temperature was 38°F. It’s truly wonderful to find these tiny little flowers growing where you least expect them!

          

     

     

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