Rocky Mountain Bighorn Sheep and Lambs on the cliffs above Bear Creek
What a treat! Two Rocky Mountain Bighorn lambs, born within the last couple of days, appeared around noon today on the cliffs across from Casitas de Gila Guesthouses on Bear Creek. Becky noticed the babies running along the side of the cliffs (amazing!) and had me get the camera. So exciting and wonderful to be able to watch new-born wild animals right outside our door!
The two ewes we blogged about in early January stayed here on the cliffs up until about three weeks ago, with only a few absences for three or four days at a time. The big ram never returned. It almost seemed as if he told the ewes, “You stay here, where you’ll be safe, and you have good water and food, until the babies are born”. As the weeks went by, Becky and I noticed (or at least convinced ourselves) that the two ewes seemed to be getting more rotund. Then three weeks ago they disappeared. We were worried. Did a mountain lion get them? Did they just decided to move on?
They are so small! And boy, can they get around already!
Three days ago, I noticed that three ewes appeared on the cliffs. The next day two Casita guests who had been hiking along the creek told us they had encountered five sheep below the cliffs eating the new grass along Bear Creek. They thought there were four ewes and maybe one young ram. They related how they had retreated back a safe distance on the opposite side of the creek so that they would not scare the sheep and proceeded to watch and photograph them. They were really quite excited because not only had they seen Bighorn Sheep, but on their way back to their Casita they came upon six young mule deer drinking from the creek and eating the new grass!
There was no way of telling if the two ewes that had been here were part of the new group of five, but the thought that they might have returned to have their babies was exciting. But yesterday, despite repeated inspection of the cliffs, I could find no sheep and concluded that this must be another group of sheep passing through …
Time to eat!
But, no! There they are! We’re sure they are the same ewes that came all winter, and now they have babies, no more than 1 or 2 days old! Already those baby sheep are running along the vertical cliffs! It’s truly something to see and we, and our guests, are very, very blessed.
Ahh! Becky finds just the right pool at the Turkey Creek Hot Springs!
There is something deeply primal about the allure that hot springs have over people. Just where within our psyche or corporeal being this attraction lies we may never know. Yet for most of us, it is there. Latent, perhaps, until one comes upon that first warm seep or gush of hot water bubbling up mysteriously from somewhere deep below. Cool springs encountered in the wild don’t appear to have the same effect. While interesting and refreshing, and certainly much appreciated on a long dusty trail on a hot summer day, cool springs do not seem to trigger the deeper emotional response as geothermal hot springs. As humans, we are drawn to warmth. We prefer sitting by the fire instead of in a cold corner; we enjoy hot showers, but endure cold ones. Our bare skin relishes the warmth of the summer breeze, but shrinks from the cold wind on a raw winter’s day. Could it be just a comfort thing, this attraction that drives us to struggle for miles over rough terrain in the pursuit of that one more distant hot spring? For some, perhaps, that is all it is, just another pursuit of pleasure. But for many it seems to be something far more, something that resonates at a much deeper level, the ineffable feeling that overcomes one while soaking in a hot pool in the middle of Wilderness …
The pools at Turkey Creek Hot Springs
The Gila Wilderness and surrounding Gila National Forest are blessed with numerous hot springs, most in untrammeled, pristine Wilderness. Some are well known and can be accessed easily, such as the Gila Hot Springs located just off State Highway 15 on the way to the Gila Cliff Dwellings, or Lightfeather Hot Springs (aka Middle Fork Hot Springs) a half-mile hike from the visitor center at the Gila Cliff Dwellings. Others are less well known, requiring moderate to difficult hikes in rugged country, such as Jordan Hot Springs, about 8 miles up the Middle Fork of the Gila River, or Turkey Creek Hot Springs, on the south side of the Gila Wilderness.
Yet as special as these and other known hot springs are, for many it is the mystique surrounding the unknown hot springs of the Gila that brings them back to this rugged landscape again and again, each time being drawn ever further into this very special Wilderness in search of what they know must be there. As one slowly begins to unravel and understand the ancient volcanic history of this little-known Gila backcountry, the realization soon comes that there must be countless other geothermal seeps, hot springs, and pools out there, their location long forgotten, places now visited only by the birds and animals. That is unless you are willing to consider the spirits of a hundred generations of Native Americans, and more recently, perhaps, the spirits of a few frontier prospectors or hermits who once called the Gila home.
Sunset over the Gila Wilderness from the Mile Long Ridge on FR155
Turkey Creek Hot Springs are not far from Casitas de Gila Guesthouses, only about 11 miles as the crow flies. However for us less-feathered-endowed mortals to get there and back, it will require a difficult physical journey, plus a good 10 hours of time. Though not for the faint of heart or the out of shape, a visit to the Turkey Creek Hot Springs promises the intrepid hiker or naturalist an intimate and inspirational sojourn into the very essence of the incredible Gila Wilderness. As special as this hike is, though, it is critical to know that access to the Turkey Creek Hot Springs is NOT always possible. High water and length of daylight hours are the two limiting factors, the most favorable times of the year being April through late June, and late September through early November. During these times the Spring runoff and the Summer rains and flash floods are generally not a problem; plus, there are enough daylight hours for a one-day visit. This is remote, rugged Wilderness and visitors who are not from the area are strongly advised to check with local authorities (such as the Gila National Forest District Ranger Station in Glenwood) before attempting a trip to the Turkey Creek Hot Springs.
I had been hearing about the wonders of Turkey Creek Hot Springs ever since we came to live here 12 years ago, but not until last week did I finally have the opportunity to visit them with my good friend and neighbor Bill Marcy and a couple of his visiting family members, John and Becky. Bill is a local hiking guide in our area, and enjoys taking tourists and visitors to special, out-of-the-way places, such as the Turkey Creek Hot Springs.
John and Becky fording the Gila River
The drive to the trail head from Casitas de Gila Guesthouses takes close to an hour. The first five miles pass quickly, driving through hilly ranch land covered with juniper, piñon and mesquite, along the less-travelled portion of Hooker Loop before returning to State Road 153 (aka Turkey Creek Road). Turning north towards the mountains, SR 153 soon becomes Forest Road 155 (still aka Turkey Creek Road). For the next nine miles one travels a rough, winding, gravel road that leads deep into the Gila National Forest. While a 4-wheel drive vehicle is not necessary, high clearance, good tires, and good brakes are strongly advised. Leaving the Gila Valley, FR 155 climbs abruptly and steeply into the lower hills and mountains of the Piños Altos Range to top out along a mile-long grassy ridge at 5,800 feet, sparsely vegetated with piñon, juniper, prickly pear cactus, and sotol agave. Upon ascending this ridge, one immediately encounters a most spectacular panoramic view extending every direction. So incredible is this view that it is impossible not to stop and get out to experience fully the vast natural grandeur of the Gila.
Sycamore Guardians of Turkey Creek
Looking north, the interior mountain peaks of the Gila Wilderness soar majestically upward from the deep canyon tracing the course of the Gila River hidden far below. To the east rocky cliffs of Gila Conglomerate outline the course of the Bear Creek drainage basin stretching upstream some 20 miles to Piños Altos, a few miles north of the volcanic peak of Bear Mountain looming on the far horizon. Five miles to the south, Turtle Rock and Telephone Mountain mark the location of Casitas de Gila Guesthouses in Bear Creek Canyon below, and further on the undulating range of the Burro Mountains makes up the southern skyline. Now turning to the west, the eye is treated to the verdant course of the Gila Valley that can be traced for miles, the Gila River itself hidden deep amongst the ancient cottonwoods lining its banks. Standing there, an awareness soon creeps into one’s consciousness that here, spread out in every direction, is the essence of Southwest New Mexico, and it is indeed a Land of Enchantment!
Continuing on, the road now drops off the ridge and begins a long and winding descent into Brushy Canyon, to eventually bottom out on the Gila River Floodplain where the trailhead to Turkey Creek Hot Springs is waiting. In years past it was possible to drive another half mile before coming to the first fording of the Gila River. But now, due to a portion of the road being washed out during a flood, a barricade of large boulders announces that it’s time to park Bill’s Bronco and start hiking.
Bill demonstrating good balance
The first half mile of the trail takes us along the remainder of the washed-out road, passing beneath the arching branches of a grove of ancient cottonwood and white-trunked sycamore, the cottonwoods resplendent in their new yellow-green leaves. Soon we encounter a calf-deep ford crossing the Gila River, the first of three that must be crossed before reaching the mouth of Turkey Creek Canyon. A couple of our party pause to change into canvas footwear which they will wear until the final crossing is left behind. The clear water is rather cold, but unnoticed in the warm, late morning sun, the eastern peaks before us gleaming and beckoning us onward.
The last crossing is soon reached, the deepest of the three, but still only up to one’s knees. At this point the trail leaves the River and enters Turkey Creek Canyon. Almost immediately we come to the remains of an old wooden corral and loading chute, an ancient windmill, and a couple of collapsing buildings, remnants of ranching days gone by, now all but reclaimed by the encroaching Wilderness.
Slow going, but gorgeous
The trail up Turkey Creek is a journey of indescribable beauty. Mostly sticking to the west bank of the creek, it leads us on a marvelous Spring adventure into an ever-deepening canyon of vertical, multicolored volcanic walls that soar into the cobalt sky beneath the eccentric tangle of bone- white branches of mature sycamore reaching for the sky, their Spring buds just starting to swell. At first only a trickle, the flow of Turkey Creek slowly increases as we make our way northward. The canyon gradually narrows as the boulders of volcanic welded tuff scattered within and along the creek increase in size and number.
Two miles up Turkey Creek we come to a lovely, spacious, and inviting camping area on the west side of the Creek within a delightful grove of mixed pine and hardwood. The canopy of piñon, gray oak, walnut, ponderosa, sycamore, and ash provide a cool, shady respite from the warming sun. It is obvious from the old rock-lined fire pits that this has been a favorite camping site for many, many years. Yet it has been well cared for by those who stopped here, with no trash in sight anywhere.
Bill in The Keyhole
A couple of hundred yards past the camping spot we come to the only critical fork in the trail for those seeking the Turkey Creek Hot Springs. Very easily missed, and only marked with a couple of small cairns of stacked rocks, the little-used trail to the hot springs forks off to the right while the more heavily-used Skeleton Canyon Trail bears to the left before crossing the dry wash at the mouth of Skeleton Canyon, and then begins a steep climb up a series of switchbacks to continue north along a high ridge between Turkey Creek Canyon and Skeleton Canyon. We take the right fork and continue up Turkey Creek Canyon, which immediately becomes narrower and more difficult to traverse.
The trail soon achieves faint to non-existent status, requiring increasing amounts of scrambling over large boulders and precipices and back and forth rock hopping across shallow, crystal clear pools in the Creek. But as the pace slows and the difficulty of forward progress increases, the physical beauty of the journey increases proportionately. Large, recessed alcoves of overhanging rock and layered ledges of black, shattered, glassy volcanic rock called vitrophyre, with enclosed splatter-shaped inclusions of deep red jasper-like material and crystal-lined geodes, repeatedly slow this geologist’s progress to a standstill. Entering the Narrows, we slowly pick our way along the rocky cliffs now extending to the water’s edge. And then, there it is: The Keyhole, through which all seekers of the Springs must pass, crawling and wiggling on one’s belly like a snake, praying with each wiggle and grunt that the real ones are not around and that we are indeed as slim as we think we are! Once safely through the keyhole, one is immediately confronted with another challenge: The Squeeze, a 100-foot-long narrow cleft of delightful scrambling consternation.
The big pool at Turkey Creek Hot Springs
Once past the squeeze, the way becomes easier. After a final tenth of a mile and negotiating one last rocky ledge, a deep, elongated pool, complete with a rock slide and waterfall at its upper end, announces that we are there: Turkey Creek Hot Springs!
What a marvelous and fascinating place! A series of pools, some completely natural, some enhanced with hand-laid rock dams, stretch upstream from the elongated pool. The various sized pools offer enough variation in temperature to satisfy even a hiking Goldilocks, ranging from too hot to too cold to just right. The control for the variation is, of course, Mother Nature herself, as the cold waters of Turkey Creek mix with the 150–165 degree geothermal waters that seep, flow, and bubble from innumerable cracks and crevices both within the smooth rock and sandy bottoms of the pools and from the adjoining rock ledges.
So many pools, so little time!
As with all warm and hot springs, wherever they are found around the globe, the hot springs of the Gila do have the amoeba Naegleria fowleri, which are extremely dangerous to humans if allowed into the nasal passages, causing primary amoebic meningoencephalitis or PAM. While infection is extremely rare, it is usually deadly. According to the medical experts, the amoeba can only enter through the nose, so keeping one’s head out of the water or wearing a nose clip is considered sufficient protection (more detailed info in references below).
What is the source of these hot waters, one might wonder? Well, far beneath Turkey Creek Hot Springs, as well as beneath most of the Gila Wilderness, lies the now solidified, but still slowly cooling, magma chamber that once fed the repeatedly explosive volcanic Bursum Caldera and its northern neighbor the Gila Cliff Dwellings Caldera some 28 million years ago. The evidence for these massive eruptions is the thick deposits of volcanic pyroclastic flows and welded tuffs that are found throughout the Gila Wilderness and through which we have travelled this entire day. But here, deep within Turkey Creek Canyon, even more tangible are the hot springs themselves, a sensuous, primal reminder of just how wild this part of the West once was.
Gila Moon Rising!
A well-earned leisurely lunch is followed by a closer land inspection of the various pools by Bill, John, and myself, leaving Becky to conduct a systematic aquatic survey of the thermal variation of several of the more inviting pools and natural water slides. Great fun!
The trip back goes quickly, more direct since we know the way; 4.5 miles as opposed to the 5 mile hike in according to the GPS. In two hours of fast hiking, we arrive at the Gila River, where, just as we begin our first ford, we come across some large, fresh mountain lion tracks right where we had passed that morning. What a great reminder they are of the Wilderness that we have travelled today, that there are places where the imprint of Nature still reigns supreme. Just as we arrive back at Bill’s Bronco, a near-full moon rises over the volcanic rock cliffs, now golden in the setting sun. Wow! How perfect is that!
The Old Windmill
Traversing The Squeeze
More hot pools
Native grass along Bear Creek
Signs of Spring are everywhere on Bear Creek now. At last, our long, cold, dry La Niña Winter is over and the dormant, monotone-gray vegetation along Bear Creek is waking up. While a few late starters are still sporting furry whitish-yellow catkins, most stands of the Bluestem Willow (Salix irrorata), which grows in spotty thickets along the Creek, have progressed to putting out their first small green leaves. Shiny deep-green clumps of native grasses have also poked up here and there along the water’s edge, much to the delight of the Mule Deer and Rocky Mountain Bighorn Sheep who come down from the adjacent hills to drink and feast.
Yet as interesting and as promising as these and other first signs of Early Spring may be, it is the electric yellow-green leaves of Freemont’s Cottonwood (Populus fremontii), now lighting up in abundance throughout the Bear Creek floodplain, that command one’s attention, their borderline-garish verdant display simply impossible to ignore. Hiking along Bear Creek, one’s eye is repeatedly entrained in silent awe of these magnificent cottonwoods, as both young and ancient specimens alike stand illuminated in the brilliant, hard, early-morning light, silhouetted against the reddish-tan conglomerate cliffs rising precipitously in shadow from the floodplain across from Casitas de Gila Guesthouses.
Freemont's Cottonwood showing its spring colors along Bear Creek
Fremont’s Cottonwood is one of several species of cottonwoods found in the US, and is the dominant species found throughout the Southwest United States, in Arizona, California, New Mexico, Nevada, Texas, and Utah. It is a large tree, attaining heights of up to 120 feet, with diameters of 5 feet or more, and a crown often spreading in excess of 100 feet. The bark, while smooth in younger trees, becomes deeply fissured as the tree matures.
Fremont Cottonwoods are dioecious, putting out flowers from March to April in the form of a long, drooping catkin that differ between male and female trees. The fruit consists of egg-shaped capsules which split open when mature to release quantities of wind-dispersed seeds carried by tufts of cotton-like filaments, often covering the ground like snow. Leaves are heart-shaped, 2 to 3 inches long, a shiny deep green with white veins and serrated margins. In the Fall, these leaves turn a beautiful deep yellow to orange, turning the floodplain into rivers of gold when viewed from the hills and mountains above. Leaves are attached to the stems by a 1-1/2-to-3 inch long vertically-flattened petiole which produces the characteristic fluttering in the slightest of breezes.
Spring cottonwoods along Bear Creek
Cottonwoods are water-loving trees, with their deeper roots extending below the permanent water table. The wood is much like a living sponge, and the heavy, water-saturated branches are highly prone to breaking off in high winds. While inviting for shade and refuge, they can be deadly for campers during a storm. Normal life span is referenced as being 130 or 150 years; but in certain favorable and protected sites this could well be exceeded by many, many years. The largest known specimen recorded in the National Register of Big Trees is in Santa Cruz, Arizona, measuring 42 feet in circumference, over 13 feet in diameter, 92 feet in height, and has a spread of 108 feet.
A cottonwood leafing out in the Spring
For many a pioneer wagon-train family crossing the dry, parched wilderness of the American West, their water barrels running dangerously low, the sight of that distant sinuous band of Spring green to Autumn gold cottonwoods snaking across the landscape was the tangible godsend to their prayers. They knew that cottonwoods meant water – either at the surface or shallow enough to dig. They also knew that beneath those lofty, rustling boughs awaited a welcomed cool, shady respite from the incessant, searing rays of the Western Sun.
Many of these pioneers would put down their own roots along these cottonwood-lined valleys. “No need to go further”, they would say, “it looks mighty fine right here”. Some would try their hand at farming, finding out fairly quickly that cottonwoods, while not much good for firewood or fodder for their animals, made a decent fencepost. Others, with more expansive dreams, would end up ranching the adjacent hills and mountains that spread out in endless emptiness before them, quickly learning to site their homesteads on the hillsides well above the reach of the floods that would periodically rage through the ancient cottonwood groves below. In time, quite a few of them would choose a more obsessive path, that of eternally chasing the illusive golden flakes that occasionally could be found shining enticingly in the stream beds beneath those same cottonwoods in the clear, shallow waters of the deeper canyons. And so it was in the valley of New Mexico’s Gila River and along the more hidden meanderings of Bear Creek. All the while the cottonwoods watched in soft, rustling observance.
To the Native Americans of the American West, however, the cottonwoods were much more than just a cool drink in a shady spot. For countless generations of various tribes, cottonwood trees were an integral part of daily life whose cultural uses ranged from offering a sacred connection to the Great Spirit to being Nature’s provider of everyday basics, from medicinal to edible to the utilitarian, and, sometimes, to the special. Several of these specific uses are listed below.
Fissured Bark on The Old One, along the Big Tree Trail at Casitas de Gila Guesthouses
Native American tribes associated with these uses, as documented in reference literature, are indicated by numerals in parentheses following the specific use. These tribes and their locations are as follows:
1 Cahuilla, Central Southern California
2 Chumash, coastal areas of Central and Southern California
3 Diegueno (Kumeyaay), Southern California and Baja California, Mexico
4 Havasupai, Grand Canyon, Arizona
5 Hopi, Northeastern Arizona
6 Hupa, Northern California
7 Kawaiisu, Southen California
8 Maidu, Northern California
9 Mendocino, Northern California
10 Pima, South Central Arizona and Sonora, Mexico
11 Pueblo, Arizona and New Mexico
12 Wintun, coastal area Northern California
13 Yokut, Central California
14 Yuki, Northern California
In reviewing the uses listed below, it is highly probable that many, if not most, other Southwest tribes besides those listed used Fremont Cottonwood in most of the various ways listed, particularly in the medicinal and edible categories.
Medicinally, the uses were legion, in the form of infusions (steeping of plants in water or oil), decoctions (mashing, then boiling of plants to extract soluble oils and organic compounds), or as poultices (soft, moist mass of plants put on injuries or bites, generally applied heated). Primary active ingredients are salicin and populin, which are closely related to the chemical ingredients of aspirin:
Infusion of bark and leaves on cloth tied around head for headaches (1)
Infusion of bark or leaves taken for colds (14)
Infusion of bark or leaves taken for sore throats, fever or (14)
Infusion of bark and leaves used as a wash for cuts (1)
Infusion of bark or leaves taken for cuts and sores (14)
Infusion of bark or leaves taken to expel worm and intenstinal parasites
Infusion of leaves applied to bruises, wounds or insect stings (3)
Infusion of leaves effective against scurvy, urinary infections, heart troubles, and as a diuretic
Infusion of bark and leaves used on horses for saddle sores and swollen legs (1)
Decoction of bark used as a wash for bruises and cuts (9)
Decoction of bark used as a wash for horse sores caused by chafing (9)
Decoction of plant used as a bark for sores (10, 14)
Decoction of green leaves used applied to breaks or sprains (3)
Decoction of inner bark to wash broken limbs (7)
Poultice of leaves applied to bruises, wounds or insect stings (3)
Poultice of inner bark applied to injured areas (7)
Poultice of boiled bark and leaves applied to swellings caused by muscle strain (1)
Poultice of hot leaves applied to breaks or sprains (3)
Poultice or salve of leaf buds used for burns or skin irritations
Use as an edible food source:
Young, green pods or “berries”(female flower catkins) eaten or chewed as gum (4, 10)
Catkins (male flower catkins) eaten as a snack food (10)
Flowers (male and female catkins) eaten as a snack food (10)
Sweet and starchy sap consumed raw or cooked
Inner bark can be scraped off and eaten raw, cooked in strips like noodles or dried and powdered as flour substitute
Various utilitarian uses:
Pealed stems split and used to make baskets (4)
Wood used for the construction of shades and houses (4)
Twigs used for basket making (8, 10, 13)
Roots used to make twined baskets (6)
Wood used for fence posts (4, 10)
Trunks used to make wooden mortars (1)
Wood used to make bowls and plates (4)
Wood used occasionally but considered a poor source of firewood (3, 4, 9)
Inner bark fibers used to make skirts (2, 12)
Bark fibers used to pad baby cradles (12)
Central pole used in the Sacred Sun Dance Ceremony (numerous Plains Indian tribes)
Roots used for the carving of sacred Kachina dolls (5)
Hollowed logs used to make drums (4, 11)
Falling seeds used to indicate time to plant (4)
Wind rustling leaves believed to be gods speaking to people (5)
The Old One — the big cottonwood along the Big Tree Trail
Most of the trails in the Casitas de Gila Nature Preserve along the Bear Creek floodplain have extensive stands of Fremont Cottonwood. The growth of the younger cottonwoods in the central part of the floodplain since a major flood in February 2005 (8 feet above normal flow, bank to bank) is well documented in the Casita’s Self-Guided Nature Trail.
The Big Tree Trail leads past several old-growth and very large cottonwoods, including one giant specimen that measures 27 feet in circumference (8.6 feet in diameter)! This tree is well protected from floods and high winds by vertical ledges of Gila Conglomerate that buttress its east side. Thus protected, it is thought that this tree is probably the oldest tree on the property, possibly in the neighborhood of 200 to 250 years. To pause and sit quietly on the log bench placed at its base and to contemplate and listen to the fluttering leaves rustling far above is a treat for one’s soul. Judging by the numerous tracks commonly found in the trail next to this tree, it is apparent that this is a favorite spot for other residents of Bear Creek as well. Examining these tracks over the years, we and our guests have identified a wide variety of passerby fauna, including Bobcat (Lynx rufus), Coatimundi (Nasua narica) and even the occasional Mountain Lion or Cougar (Felix concolor).
Thanks to the Discovery Channel, the National Geographic Channel, the BBC, and other mass media documentaries, most people have heard of super-volcanoes: large-scale geologic features, which when they become active, can spew 1,000 cubic kilometers (240 cubic miles) or more of ejected material in the form of lava, molten rock fragments and ash over vast areas of the surrounding countryside and into the atmosphere.
Technically referred to by volcanologists and geologists as calderas or mega-calderas, the best-known super-volcano of the United States is the Yellowstone Caldera. In recent geologic times the Yellowstone Caldera has had three super eruptions: 2.1 Ma (million years ago), 1.3 Ma, and the most recent only 640,000 years ago, when about 1000 km3 of volcanic material was blasted into the air, covering much of North America with up to 2 meters of ash and volcanic rock debris.
Snow-covered layered volcanic tuffs from the Bursum Caldera in the Piños Altos Range in the Gila Wilderness as seen from Casitas de Gila Guesthouses
Calderas form when a hot spot of molten magma develops in the lower crust or upper mantle of the earth, causing the surface of the earth to bulge up under the extreme pressure of molten rock with trapped gases within the magma chamber. If the composition of the magma is rich in silica, say 60% to 70%, the molten rock is highly viscous and not likely to flow easily (unlike the silica deficient [50% or less] basaltic lavas of Hawaii which flow readily for miles and miles). Consequently, when the upward-moving molten silica-rich magma nears the surface of the earth, it undergoes a rapid drop in confining pressure from the overlying rock that allows for the decompression and expansion of the trapped gasses in the magma. When this occurs, it results in the explosive and destructive eruption of the volcano, and the spewing of the voluminous amounts volcanic ash and other volcanic material. Once the eruption and the emptying of the magma chamber is complete, it is then that the distinctive geomorphic landscape of the caldera forms.
Calderas are so named because of the cauldron-like shape that results from the collapse of the interior land surface of the center of the volcano following the eruption and emptying of the underlying magma chamber. Super-volcanoes or mega-calderas can be huge: the Yellowstone Caldera, for example, measures 30 miles by 45 miles. Oftentimes mega-calderas will experience repeated cycles of resurgent doming of the caldera floor as more molten magma rises to the surface of the earth, followed by renewed eruptions and collapse. Super-volcanoes can wreak havoc on a monumental scale, with devastating climate and ecological affects felt on a world-wide basis, including mass extinctions of species and mini-ice ages.
The Mogollon Range in the Gila Wilderness with layered volcanics from the Bursum Caldera
While most of today’s visitors to Yellowstone National Park are aware of the Park’s explosive past and unstable present, it is fairly safe to say that it would be the rare visitor to Southern New Mexico who would have any idea that the seemingly benign and now silent Gila Wilderness, which forms the spectacular mountainous skyline just 5 miles to the north of Casitas de Gila Guesthouses, shares a similar, albeit much older and complex, geologic history. It is here, in the Gila Wilderness, over a span of some 15 million years, that Southern New Mexico was witness to one of the most explosive and largest areas of continuous volcanic activity in the world, and one which rivaled every aspect, in terms of overall size and magnitude of ejected volcanic material, of its Yellowstone counterpart, 700 miles to the north.
The Catwalk Narrows cut by Whitewater Creek in Cooney Tuff from the Mogollon Caldera
Geologic research in the Gila and Aldo Leopold Wildernesses and surrounding Gila National Forest shows that this area has been the site of at least 4 major mega-calderas that were active over a span of time from 35 to 20 million years ago. From West to East these are: the Mogollon Caldera, the Bursum Caldera, the Gila Cliff Dwellings Caldera, and the Emory Caldera. These calderas formed within a vast volcanic landscape referred to as the Mogollon-Datil volcanic field, which stretches some 100 miles from Datil south to Piños Altos.
Few exposures remain of the oldest caldera, the Mogollon Caldera, dated at 34 Ma (34 million years ago), which was active during the Late Eocene and Early Oligocene epochs. This caldera was located in what is now the heart of the Mogollon Mountains, the imposing mountain range which extends northwest from the community of Gila towards Glenwood and then turns north towards Reserve. Although the Mogollon Caldera is typically covered over by younger volcanic deposits, a lot of what is known about it has been gleaned from research done along Mineral Creek near Alma and at the Catwalk Recreation Area, where exposures of a portion of the rocks which made up the wall of the collapsed caldera can be found along the east side of Whitewater Creek Canyon near the beginning of the Catwalk Trail. The size of the Mogollon Caldera is not known due to the cover of younger volcanic material; however, judging by the combined thickness of the pyroclastic rhyolitic ash fall and ash flow tuffs of the Cooney Tuff formation, which totals about 3,000 feet, it is highly probabe that this caldera was immense.
Cooney Tuff from the Mogollon Caldera, along the Catwalk Nature Trail in Glenwood
A few million years later, during Early Oligocene time, approximately 29-28 Ma, renewed vulcanism once more took place within the Mogollon Mountains just east of Glenwood. This activity culminated in the formation of the huge Bursum Caldera, which measures some 18 miles by 25 miles across. Once again, massive and explosive eruptions of pyroclastic rhyolitic ash fall and ash flow deposits took place, burying most of the Mogollon Caldera deposits, with what is now known as the Bloodgood Canyon Rhyolite Tuff and the Apache Spring Tuff formations.
Contemporaneous with, and overlapping the eastern margin of the Bursum Caldera, the smaller Gila Cliff Dwellings Caldera, 28 Ma and measuring some 10 miles by 16 miles in diameter, was busily erupting, blowing out extensive deposits of rhyolitic pyroclastic ash flow and ash fall material to form what is now mapped and known as the Shelly Peak and Davis Canyon tuffs.
The Emory Caldera, 34 Ma and measuring some 15 miles by 34 miles in diameter, is the eastern-most caldera within the Gila National Forest, lying partly within the Aldo Leopold Wilderness at the southern end of the Black Range near Hillsboro and some 15 miles east of the eastern edge of the Gila Cliff Dwellings Caldera. Like the other calderas in the Gila Wilderness, the Emory Caldera ejected tremendous quantities of pyroclastic rhyolitic ash fall and ash flow deposits such as the Kneeling Nun Tuff, which is the material which makes up the unusual rock formations at City of Rocks State Park, 25 miles south of Silver City.
Cliffs of Cooney Tuff from the Mogollon Caldera along the Catwalk Trail in Glenwood
If the above geologic history and descriptions of rocks comprising each of the four Gila calderas sounds similar, that is because they are. The reason for this is that current geologic and geophysical data and research suggests that these four caldera, while coming from separate and shallow magma reservoirs, were being fed from a much larger, deeper and common magma chamber, which in geologic terminology would be called a batholith.
Following the eruptions and collapse of the calderas of the Gila Wilderness and surrounding area, extensive mineralization emplacement took place, including precious and base metals such as gold, silver, lead, zinc and copper, and non-metallic fluorite. This mineralization occurred within the ring faults surrounding the calderas, plus a host of other associated faults and intrusive dikes structures within and adjacent to the calderas. With the discovery of this mineralization in the mid-1800s, mining became the major driving economic force leading to the settlement and development of Grant and Catron Counties, with the establishment of several early mining districts in the area, such as the Cooney Creek-Mogollon mining district, where mineralization has been dated at 17 Ma, the Piños Altos gold mining district, and the Gila fluorspar mining district located near Gila at the mouth of the Gila River Canyon which was developed during WWII.
Agave growing on Cooney Tuff from the Mogollon Caldera along the Catwalk Nature Trail in Glenwood
In addition to the emplacement of mineralization, other late-stage volcanic activity continued in association within the calderas and surrounding area with the eruption of basaltic andesite flows about 26-25 Ma and additional rhyolite and basaltic flows around 22-21 Ma. Gradually, such activity decreased as the deep magma chambers cooled, although even as late as 5.5 Ma basaltic flows still occurred from time to time in the area, as evidenced by the presence of these flows interbedded within the Gila Conglomerate adjacent to the Mogollon Mountains, such as those observed about five miles east of Casitas de Gila Guesthouses in the Bear Creek drainage.
Today, many visitors to the Gila Wilderness come to enjoy the remnant heat from these ancient fiery, super-volcano calderas in the form of the numerous hot springs that are found throughout the area. While some of the springs are well known, such as the Gila Hot Springs and Turkey Creek Hot Springs, countless others await their discovery by the intrepid hiker explorer. To be sure, while the fire down below may be out, the oven is still plenty hot!
Ratte, J. R. Marvin, C. Naeser, and M. Bikerman, 1984, Calderas and Ash Flow Tuffs of the Mogollon Mountains, Southwestern New Mexico, Journal. Geophysical Research. 89(B10), 8713-8732.
Ji. C. Ratte, S. Lynch, and W. C. McIntosh, 2006, 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 OF-GM 120.
Geology of the Gila Wilderness- Silver City Area, 2008, New Mexico Geological Society, Fifty-ninth Annual Field Conference, October 23-25, 2008, New Mexico Geological Society, Inc.