A MID-WINTER DAY’S SEARCH FOR CHALCEDONY AND FIRE AGATE
AT ARIZONA’S BLACK HILLS ROCKHOUNDING AREA
Fire-agate and chalcedony collected at Black Hills Rockhound Area
THE SOUTHWESTERN NEW MEXICO AND SOUTHEASTERN ARIZONA BORDER COUNTRY
– A ROCKHOUNDER’S PARADISE
The three physiographic regions of Arizona: Colorado Plateau Region, Mogollon Rim Transition Zone which includes the Mogollon-Datil Volcanic Field, and the Basin and Range Province (Wikimedia Commons: Mortadelo 2005)
The Southwestern New Mexico and Southeastern Arizona Border Country offers some of the finest and most diverse rockhounding opportunities to be found anywhere in the Southwest. Semi-precious gems, minerals, and rocks of an extremely wide diversity can be found here, including white to pink chalcedony, fire agate, banded agate, red and yellow jaspers, carnelian, obsidian, geodes and thunder eggs, and banded rhyolites, as well as exotic copper minerals like turquoise, malachite, azurite, and chrysocolla. These are but a few of the treasures that can be hunted and collected here, scattered over the surface on many thousands of acres of public lands, as well as excellent specimens that can be dug from the tailings dumps at numerous abandoned gold, silver, and copper mines that operated in the late 1800s and early 1900s.
The reason for this great abundance and diversity of collectable rocks and minerals is that the Southern New Mexico-Arizona border straddles a complex geological transition zone encompassing the eastern edge of the Basin and Range Province and the southwestern side of the Mogollon-Datil Volcanic Field at the southern end of the Colorado Plateau. During the Oligocene and Miocene Epochs of the Mid-Tertiary Period between 35 and 15 million years ago, this vast area in the American Southwest was the site of repeated episodes of extensive faulting, vulcanism, and extensive mineral vein intrusion, each of which are critical factors favoring the formation of unique and desirable specimens sought by the avid rockhound. Situated just 30 miles east of the New Mexico-Arizona border, Casitas de Gila Guesthouses is located in the heart of this rockhounding paradise. As such, no matter which direction one takes from the Casitas on a single day’s outing, there are excellent collecting sites to be discovered.
FIRE AGATE: THE PREMIER SEMI-PRECIOUS GEMSTONE
OF THE SOUTHERN NEW MEXICO-ARIZONA BORDER COUNTRY
An exceptional piece of high grade fire agate in the rough from Slaughter Mountain, AZ, showing beautiful fire agate just beneath an enclosing layer of semi-transparent chalcedony (Wikimedia Commons: Maricopa Mining LLC )
One of the semi-precious stones most highly sought after by rockhound guests staying at the Casitas is fire agate. Fire agate is a type of chalcedony (SiO2) which contains multiple, extremely thin layers of the iron oxide minerals of Goethite (FeO(OH)) and Limonite (FeO(OH)·nH20) imbedded within, and commonly completely enclosed by, semi-transparent to translucent layers of cryptocrystalline chalcedony. When cut and polished down to the layers containing the iron oxides, the stone displays a metallic, shimmering iridescence known as the Schiller Effect, where light is reflected and refracted off the various layers containing the Goethite and Limonite iron oxides to give the exquisite play of colors—or “fire”—for which the gemstone is named. Colors displayed by the “fire” vary greatly, the most common being shades of orangish brown, but also all shades and tones of yellow, orange, red, and green, and more rarely, purples and blues.
Semi-transparent and translucent chalcedony as collected at Black Hills Rockhound area February 10, 2016
Pure chalcedony, while composed of only cryptocrystalline SiO2, is actually a very fine intergrowth of two separate minerals, quartz and moganite, which have the same chemical composition but differ in their crystal structure. In the New Mexico-Arizona border country, chalcedony is typically found in shades of translucent white to pink and light grays and blues. It commonly displays a waxy luster and botryoidal texture.
HOW FIRE AGATE AND CHALCEDONY FORM
The fire agate and chalcedony of the Southern New Mexico–Arizona border area is formed when low pressure and low temperature epithermal hydrothermal waters (50°-200°C / 122°-392°F) carrying colloidal SiO2 and iron oxides are injected into cavities in volcanic rocks such as gas bubbles in flow rocks, irregular-shaped vug fillings, or along fault or bedding plane fractures. Deposition of the chalcedony can take place by the slow buildup of numerous thin layers over an extended time from watery fluids, or rapidly all at one time from viscous silica gels, which appear to have had a viscosity of tooth paste … an extremely hot tooth paste! The May 27, 2014 Blog “Seeking Chalcedony and Jasper in Southwest New Mexico” includes numerous photos on the various forms and shapes of chalcedony and fire agate that have been found at or near the Casitas over the years, and presents more details on their various modes of formation.
A DAY TRIP OF COLLECTING AT THE BLACK HILLS ROCKHOUND AREA
The Black Hills Rockhound Area is located in Arizona, 50 miles west of Casitas de Gila Guesthouses, just off US Highway 191, about 13 miles west of the crossroads community of Three Way and 19 miles east of Safford, Arizona. The site is a designated rockhound area on BLM (U.S. Bureau of Land Management) land, and is open to the public year round.
A BEAUTIFUL EARLY MORNING DRIVE OVER THE HIGH CHIHUAHUAN DESERT MOGOLLON-DATIL VOLCANIC FIELD TO THE SONORAL DESERT BELOW
The drive from the Casitas to the Black Hills Area takes about 1.5 hours, traveling on excellent highways that pass through some of the most scenic mountain country in Southwestern New Mexico and Southeastern Arizona. From the Casitas, the route goes northwest on US 180 through a High Chihuahuan Desert landscape affording magnificent views of the Mogollon Mountains before turning west on NM 78 through the incredibly beautiful Mule Creek Country.
Looking east to the Mogollon Mountains in the Gila Wilderness across the rolling grassland of Mule Creek Country just off State Road 78
Notable for having some of the finest ranch land in Southern New Mexico, the Mule Creek area is a mile-high landscape of rolling grasslands offset by a sparse scattering of Alligator Juniper trees. After passing through the tiny community of Mule Creek — don’t blink or you’ll miss it! — the road immediately enters the Gila National Forest where it begins a gradual six-mile climb over the northern extent of the Burro Mountains before crossing into Arizona and entering the Apache National Forest at an elevation of 6,000 feet.
Looking southwest across High Sonoran Desert from the overlook on State Road 78, 5.6 miles into Arizona from the New Mexico-Arizona border. From this overlook at an elevation of 6,250 feet the road descends 2,650 feet over the next 14 miles to the small community of Three Way, Arizona, on the Gila River. The 10,696-foot peak of Mt. Graham commands the center skyline 52 miles in the distance.
For the next 5.6 miles the road winds through a Ponderosa-shaded mountain roadway within the Apache National Forest before reaching an amazing overlook and parking area at the edge of a major topographic, physiographic, geologic, biologic, and ecologic boundary that marks the abrupt transition from the southwestern extent of the High Chihuahuan Desert of the Mogollon-Datil Volcanic Field into the eastern edge of the High Sonoran Desert of the Basin and Range Province. The westward view from this overlook affords a marvelous long-distance view into the Sonoran Desert Country within the Basin and Range Province of Arizona, with the 10,696 foot towering presence of Mt. Graham looming 52 miles to the west.
Leaving the lookout parking area at an elevation of 6,250 feet, the highway descends rapidly through a series of switchbacks and a distance of 4 miles some 1,200 feet down the face of a west-facing escarpment, leaving behind the flora and fauna of the High Chihuahuan Desert and entering the totally different natural world of the High Sonoran Desert. Upon reaching the base of the steep escarpment, Highway 78 continues a downward but more gradual descent of another 1,400 feet in elevation over the next 10 miles to arrive at Three Way, Arizona, at elevation of 3,600 feet. The change in landscape, both topographically, geologically, biologically and ecologically over this 14 mile stretch of highway is both dramatic and amazing and for most travelers will be remembered as one highlight of the day’s journey.
Entrance sign at U.S Highway 191 for BLM’s Black Hills Rockhound Area
At Three Way, Highway 78 ends and the journey continues straight ahead on U.S. Highway 191 to once again cross the Gila River and for the next 13 miles passes through a fascinating Sonoran Desert landscape of weathered and dissected volcanic hills, mountainous ridges, mesas, and sharp pinnacles or buttes, almost all of which is public BLM or State of Arizona land. At mile marker 141.6, a sign on the right (north) side of the road marks the entrance road to the Black Hills Rockhound Area.
Turning in off the highway, a well-maintain gravel road is followed for two miles to a parking area where another sign informs the visitor that they are at the center of the Black Hills Fire Agate deposit, and further states that while small pieces of fire agate can be found on the surface, large pieces will have to be dug for! Translation of BLM wordage: “the big pieces have already been picked up by somebody else before you got here.” But don’t be put off: there are still tons of collectable material out there … somewhere!
THE FIRE AGATE AND CHALCEDONY OF THE BLACK HILLS ROCKHOUND AREA
Every year during the Summer Monsoon Season intense thunderstorms expose, transport, and deposit new fire agate and chalcedony for collecting as heavy rain runoff rushes down from the higher regions of the Black Hills Rockhound Area to the lowlands below
Looking west from the prominent ridge on north side of fire agate deposit towards the parking area at Black Hills Rockhound area in center of photo, 2 miles in from US Highway 191
The Black Hills Rockhound Area is one of two designated fire agate localities on BLM land in Southeastern Arizona, the other being the Round Mountain Rockhound Area, some 27 miles to the southeast near the Arizona-New Mexico border. Both of these areas are well known and receive many visitors each year. Because of this, one might wonder if there is any material left to be collected. Actually this is not a problem for two reasons: the first being that the area at the Black Hills site where fire agate and chalcedony can be found is vast, comprising thousands of acres of public BLM land surrounding the main collecting area, some of which comprises incredibly rough and steep terrain which is rarely visited. The second reason is that because of the heavy rainfall the area receives during the annual Summer Monsoon thunderstorm rains, which can exceed 2 to 3 inches in a half hour, fire agate and chalcedony buried beneath of surface of the ground is constantly being uncovered and exposed by high energy flash flood runoff every year. Proof of this process of replenished collectable material is the fact that over the past 18 years no Casita guests visiting the area have ever returned empty handed!
Are some areas better to look than others? Of course! And in that respect, rockhounding is much like fishing:. experience and understanding of the quarry counts! And so, it is in that context that the following brief geologic overview is offered as an aid to knowing where to look for the Black Hills fire agate and chalcedony. After reading this, however, it must always be kept in mind when setting out for a day of rockhounding, that just like it is in fishing, there will always be the occasional great day, many good days, and those other days where, well, it was certainly a nice day for being out in the desert connecting with nature! But, then, isn’t that at least half of the fun anyway?
A MODICUM OF UNDERSTANDING REGARDING THE SUCCESSFUL SEARCH FOR AND RECOVERY OF THE RECLUSIVE AND ELUSIVE FIRE AGATE AND CHALCEDONY OF THE BLACK HILLS ROCKHOUND AREA
Close up of pyroclastic rhyolite ash fall welded tuff bedrock forming massive resistant cliffs at east end of ridge north of parking area
Outcrop of broken angular blocks of andesite bedrock showing abundant gas bubbles near west end of ridge east of parking area. The large cactus is the Barrel Cactus, a common plant of the High Sonoran Desert.
The geology of the Black Hills Area is not very complex. Basically, there are two main volcanic rock types of Mid-Tertiary age (Oligocene to Middle Miocene or 30 to 15 million years ago) which make up the bedrock that crops out at the surface on the tops of the hills, ridges, and small mountains that surround the Black Hills parking area. These rock types consist of 1) dark gray to reddish gray andesite lava flow rock that is deposited in a sequence of essentially horizontal layers, many of which contain abundant gas bubbles, and 2) gray to light tan, silica rich, rhyolite pyroclastic ash flow or ash fall welded tuff that overlies or is interbedded with the andesite flow rock. The andesite flow rock is the host rock for the fire-agate and chalcedony which, as explained above, forms over time through secondary deposition from hydrothermal waters containing colloidal silica and iron oxide colloids that slowly fill or are injected into cavities such as gas bubbles, irregular shaped vugs, and thin veins within the andesite flow deposits. In most cases the overall volume percentage of chalcedony and fire agate that forms within the flow rock is extremely small — much less than 1%, although examination of the vertical sequence of the Black Hill andesite deposits does show that certain layers or levels do contain more void space and hence higher concentrations of chalcedony and fire agate than others.
Both andesite and rhyolite ash fall welded tuff bedrock occur along the top of the ridge north of parking area. In this photo weathered and disintegrating blocks of andesite comprise the foreground on left, and the high promontories on far right horizon, and rhyolite welded tuff constitutes the cliffs in middle distant horizon.
Massive cliffs and large broken blocks of andesite flow rock and rhyolite welded tuff bedrock comprise the tops of a low ridge lying about a half mile to the north of the designated parking area in the center of the Black Hills Fire Agate area. On the sides of this ridge, below and surrounding the solid rock outcrops, are loose accumulations of smaller broken rock, coarse rock debris, and soil that is in the process of being carried downslope from the rock outcrops.
Andesite is composed of a high concentration of feldspar and other minerals which over time will break down physically and chemically decompose to form an unconsolidated mineral soil of clay minerals and fine rock particles, thereby releasing the contained fire agate and chalcedony which retains its original size and shape because SiO2 minerals are very stable and inert to weathering and chemical decomposition at the Earth’s surface.
Following this breakdown of the andesite bedrock, the processes of gravity, wind (desert pavement), and running water in the form of flash floods, acting over thousands of years, will carry the altered and disintegrated clay particles, fine rock debris, and the fire agate and chalcedony further and further downslope and away from the bedrock to be redeposited in and over the surrounding lowlands, flats, valleys, and washes.
As weathering of the andesite bedrock continues over time, the bedrock and large blocks of andesite found higher up on the ridge are broken down into smaller and smaller pieces and loose mineral soil which are gradually transported further and further downslope by Monsoon rain runoff. Here, on the lower slopes well below the ridge east of the parking lot an abundance of Prickly Pear Cactus indicates the presence of an increased percentage of fine sediment and mineral soil plus accompanying retention of ground moisture. Note also the numerous small white rocks in the foreground. These are pieces of white chalcedony that also become concentrated on the lower slopes through the breakdown of the andesite bedrock.
Gradually, this process will produce a thick, wedge shaped deposit of successive layers of transported sedimentary material surrounding the bedrock core of the ridge. Since the clay and finest rock particles are selectively carried furthest away by the periodic flash flood runoff from the source bedrock upslope, a concentration or lag deposit of the larger rock fragments and, of most interest to rockhounds, the physically and chemically inert pieces of chalcedony and fire agate, accumulates over the ground surface following each successive flash flood coming off the surrounding the uplands. Successive floods will, of course, bury previously deposited layers of the concentrated fire agate and chalcedony as the erosion of the bedrock upslope on the ridge continues and the wedge shaped deposits surrounding the ridge thicken.
The important result of this process is, of course, that the concentration of fire agate and chalcedony which was less than 1% in the original solid host rock may now be increased many times over in the loose, unconsolidated sediments and mineral soil, which in addition to being picked up on the surface can be successfully recovered by digging with pick and shovel.
Naturally, the big question of course is: Where does one dig? Hopefully, the above discussion offers some clues as to where to begin, and your hosts at the Casitas will be pleased to offer additional suggestions if asked. However, it must be kept in mind that it is this very same question that has perplexed every prospector in the American Southwest for over a hundred years, and in most cases it is only after much personal experience and perseverance that Mother Nature will even consider beginning to answer the question. So in the meantime, good luck in your quest and enjoy the chase!
On the hunt for the reclusive and elusive fire agate amongst the Ocotillo and Prickly Pear Cactus at Black Hills Rockhound area
A welcome lunch break in the shade of the rhyolite welded tuff cliffs at the top of the ridge
A “DAY’S CATCH” AT THE BLACK HILLS ROCKHOUND AREA
As further proof that there is still lots of good fire agate and chalcedony to be found at the Black Hills Rockhound Area, the following photos represent the best of the “Day’s Catch” over a four-hour period by your Casitas’ hosts on a beautiful early Spring day in February 2016.
A large piece of fire agate encased in translucent chalcedony
No two pieces of fire agate in the rough are the same
Only through grinding and polishing of this fire agate in the rough can the underlying beauty be revealed
Fire agate is often encased in thick layers of semi-transparent to opaque chalcedony
Pure chalcedony can take on a variety of shapes and forms, such as this strange frog-like little creature perched on this fragment of weathered andesite¬
We’re taking a break from the Gila Nature Blog for a few months in order to focus on other projects. Since January 2011, when the first Blog article appeared, a wide range of topics has been covered. Here’s a summary of several topics. If your favorite topic isn’t listed below, use the panel to the left to find your interests.
We look forward to having you as a guest at Casitas de Gila Guesthouses!
HIKING AT THE CASITAS
• Hidden Spring Trail — January 2011
• Dry Wash Trail — October 2014
• Paradise Overlook Trail — February 2015
HIKING IN THE AREA
• Turkey Creek Hot Springs Trail — April 2011
• Mineral Creek — February 2012
• The Catwalk & The Gold Dust Trails — April 2012
• Middle Box of the Gila — June 2012
• Mogollon Box Trail — July 2012
• San Francisco Hot Springs Trail — September 2012
• Lower Little Dry Creek Canyon — April 2013
• A Fall Hike — October 2013
• Upper Little Dry Creek — November 2013
• Mineral Creek in the Winter — January 2014
• Sacaton Creek – November 2014
• Sheridan Corral Trail — May 2015
• Rain Creek Canyon – July 2015
• Volcanoes — March 2011
• Obsidian – August 2012
• Fluorite – May 2013
• Chalcedony & Jasper – May 2014
• Mineral Creek – February 2012
• Coronado – December 2012
• Apacheria (Part 1) – February 2013
• Apacheria (Part 2) – March 2013
• Ancient Crops – August 2013
• San Francisco River Back Country – February 2014
• Gila Cliff Dwellings (Part 1) – August 2015
• Gila Cliff Dwellings (Part 2) – September 2015
• Billings Vista Birding Area – June 2012
• Winter & Spring Birding – April 2014
SOME OBSERVATIONS OF THE EFFECTS OF THE EL NIÑO / LA NIÑA
CLIMATIC OSCILLATION CYCLE WITHIN THE BEAR CREEK NATURE PRESERVE
AT CASITAS DE GILA GUESTHOUSES
El Niño Winter of 2015-16: Fresh snow on the Pinos Altos Range in the Gila Wilderness, five miles north of Casitas de Gila
CLIMATIC AFFECTS OF EL NIÑO AND LA NIÑA WINTERS ON SOUTHERN NEW MEXICO
Historical records show that El Niño winters in the Southwest are marked by increased precipitation and warmer temperatures, while La Niña winters are marked by decreased precipitation and colder temperatures. During El Niño years, moisture-laden low pressure systems coming in off the Pacific Ocean tend to follow a southern route, carried along by the west-to-east flow of a persistent Pacific Jet Stream across the Southwest and into southern New Mexico (see Figure 1 below.) During La Niña years, however, eastward-moving, moisture-laden low pressure systems coming in off the Pacific Ocean tend to take more northerly routes across the western U.S., carried along by the west-to-east variable flows of the Pacific and Polar Jet Streams, bringing dry, sunny high pressure conditions to prevail over the Southwest and New Mexico.
FIGURE 1: Schematic drawing showing climatic weather patterns of La Niña and El Niño for North America. Prepared by NOAA/ National Weather Service/ National Centers for Environmental Prediction.
MONITORING OSCILLATIONS OF EL NIÑO AND LA NIÑA BY THE OCEANIC NINO INDEX (ONI)
Sea surface temperatures fluctuate constantly in the Central Pacific along the equator, and when monitored and averaged over time demonstrate repeated oscillations between El Niño (warm) and La Niña (cold) episodes. The U.S. National Oceanic and Atmospheric Administration (NOAA) monitors these oscillations by averaging monthly measurements of surface sea water temperatures collected over an area that covers the central portion of the Pacific Ocean between 5°N and 5°S latitude and 120° to 170° W longitude. These temperature fluctuations, when averaged over successive three-month intervals during the year (which NOAA refers to as “seasons”), yield temperature anomalies that NOAA calls the Oceanic Niño Index (ONI). ONI values generally lie within 3°C of the average temperature for any given area at any specific time of the year. Anomalies that deviate from the average temperature in excess of +0.5°C mark a shift towards a warm El Niño episode, whereas anomalies in excess of -0.5°C mark a shift towards a cold La Niña episode. Anomalies that are between ±0.5°C are called a Neutral Episode, or, as they are sometimes humorously referred to, a La Nada episode. By NOAA’s definition, an El Niño or La Niña episode can only be so named when the average of three consecutive ONI three-month seasonal values exceed the ±0.5°C threshold.
CYCLES OF EL NIÑO AND LA NIÑA FOR NORTH AMERICA 1950 to 2015
When plotted through time as shown in Figure 2 below, it is very clear that El Nino and La Nina episodes are predictably cyclic in nature, with an average duration between 3 and 4 years. Although these episodes do show variability in both duration and intensity, they are not unusual in any way, and are just another of Nature’s cycles that has a pronounced affect upon the natural environment and plant and animal populations in the American Southwest.
NOAA graph showing 65 years (1950 to 2015) of El Niño (red) and La Niña (blue) cycles
THE TRANSITION OF THE RECENT LA NADA EPISODE OF MARCH 2012 TO EARLY 2015 INTO THE VERY STRONG EL NIÑO OF 2015 – EARLY 2016
As can be seen in the Oceanic Niño Index, the American Southwest entered a Neutral or La Nada episode beginning around March of 2012. This La Nada episode continued throughout the rest of 2012, 2013, 2014, and into the first two three-month monitoring periods of 2015. However, beginning in the third three-month interval of February/March/April 2015, the ONI shows a weak El Nino episode gradually strengthening throughout the year to become a very strong El Nino episode by December 2015. Current projections (.pdf file) as of January 4, 2016, have the strong El Niño conditions continuing throughout the rest of the 2015-16 Winter, followed by a slow transition into an ENSO Neutral episode or La Nada situation by Late Spring or Early Summer.
PRECIPITATION DATA COLLECTED AT CASITAS DE GILA ILLUSTRATE THE TRANSITION OF A PERSISTENT LA NADA EPISODE TO A STRONG EL NIÑO EPISODE BETWEEN MARCH 2012 and DECEMBER 2015
Precipitation at Casitas de Gila has been monitored electronically on a daily basis for many years. Some of this data is presented in Tables 1 and 2 below. Examination of this precipitation data illustrates the transition of a persistent La Nada episode to a strong El Niño episode between March 2012 and December 2015.
As can be seen in Tables 1 and 2, there is a marked increase in precipitation from 2012 to 2015, on a yearly total basis and also when comparing Fall and Winter month totals. The NOAA projection for the Oceanic Niño Index (ONI) for the remainder of the 2015–16 Winter is to remain in an El Niño episode, returning to a Neutral or La Nada episode in Late Spring or Early Summer. If this projection holds true, the Fall and Winter total precipitation should exceed the 2014-15 total precipitation.
SOME OBSERVED POSSIBLE AFFECTS OF THE TRANSITION OF THE LA NADA EPISODE OF 2012 TO 2015 INTO THE STRONG EL NIÑO EPISODE OF 2015 UPON THE FLORA AND FAUNA OF THE BEAR CREEK NATURE PRESERVE AT CASITAS DE GILA
Casitas de Gila is situated on the western edge of Bear Creek Canyon about 80 feet above the Creek overlooking the 265 acres, 3/4 mile of Bear Creek, and 6 miles of trails that constitute the Bear Creek Nature Preserve.
During the time period from March 2012 and December 2015, various changes have been observed in the flora and fauna of the Bear Creek Nature Preserve at Casitas de Gila Guesthouses which may be in response to the transition from the La Nada episode to a very strong El Niño episode as documented in Tables 1 and 2. Some of these observations are presented below. In considering these observations, it must be stressed that they are the result of long-term, daily, on-site personal observations only, and not the conclusions of a rigorous scientific study. It is also important to remember the important principle that must always be kept in mind when dealing with any study of Nature, namely: that “Correlation does not necessarily equate to Causation”. With those caveats stated, the following possible affects of the transition of the La Nada episode of 2012 into the strong El Niño of 2015 are presented:
OBSERVED TRENDS IN FLORA AT THE BEAR CREEK NATURE PRESERVE 2012 to 2015
The marvelous Doubting Mariposa Lily (Calochortus ambiguus) found blooming on April 25, 2015, at Casitas de Gila as a result of the 2014-15 El Nino Winter moisture; this is the first time this flower had been observed at the Casitas
• During and in the months immediately following the very dry year of 2012 (total precipitation 6.86 inches), and cold Winter of 2012-13, flowering and seed production of trees, shrubs and grasses at the Casitas were much below normal. Numerous individual plants of several species, such as the Turpentine Bush (Ericameria laricifolia) and Engelmann Prickly Pear (Opuntia engelmannii), on the Casitas’ Self-Guided Nature Trail were observed to die. Spring flowers in particular were notably absent.
• As yearly and Fall/Winter precipitation steadily increased during the transition from La Nada to El Nino, flowering and seed production likewise increased, culminating in the Spring of 2015 when a profusion of flowers occurred over the Casita lands. So profuse and obvious was this prolific flowering of diverse species (some of which had not been seen in many years, and others, such as the Doubting Maricopa Lily (Calochortus ambiguus), had never been observed or recorded previously at the Casitas), that it became the subject of two Nature Blogs in March and April of 2015.
OBSERVED TRENDS IN FAUNA AT THE BEAR CREEK NATURE PRESERVE 2012 to 2015
The Whitewater-Baldy Fire on May 22, 2012, 25 miles in the distance as viewed one mile from the Casitas
• 2012 was a year of severe drought and a very difficult time for animals both at Casitas de Gila and at the adjacent Gila National Forest and Gila Wilderness. This was also the year of the Whitewater-Baldy Complex Fire which became the largest forest fire in New Mexico’s recorded history.The fire started on the west side of the Mogollon Mountains just within the Gila Wilderness about 25 miles northwest of Casitas de Gila on May 9, 2012, when two dry-lightening strikes touched off the drought-parched forest. The resulting conflagration was finally declared controlled on July 31, after burning some 297,000 acres of the 600,000 acres of the Gila Wilderness, at an estimated cost of $100 million dollars. This incredibly destructive fire was the subject of a Nature Blog in September 2013.
The combination of the Whitewater-Baldy fire and the ongoing drought of 2012 resulted in some expected and unexpected changes in animal populations and occurrences within the Bear Creek Nature Preserve.
• With the lack of Spring rains in 2012, stock tanks in the mountains adjacent the Bear Creek Nature Preserve dried up early and normal Spring grass and shrub vegetation in the uplands was deficient to completely lacking. Consequently, Bear Creek in front of the Casitas (which always has water in it year around) saw an increase in animals, both large and small, as it was the only source of water and food around. Some of the increase was probably also due to animals fleeing the Whitewater-Baldy Fire in the adjacent Gila Wilderness. Black Bear, Rocky Mountain Bighorn Sheep, and Mountain Lion (the only predator of the Bighorn Sheep) sightings at the Casitas and on Bear Creek were up. Adult Bighorn populations seemed normal; however, only two newborn lambs were observed during 2012 at any one time on the cliffs following lambing in Late Spring. In June a mother Black Bear brought her two cubs to Bear Creek for food and water, and for the first and only time in the 18 years history of the Casitas, garbage cans were raided by the bears.
• In 2013 and 2014, precipitation increased as the overall climate moved towards the El Niño episode. In the early morning hours of September 22, 2014, the largest flash flood ever recorded at Casitas de Gila in its 18-year history occurred when the remnants of a major hurricane in Baja California triggered a series of thunder storms traveling down the Bear Creek drainage from its headwaters in Pinos Altos, creating a flood crest of 12 feet above normal Creek level. The effect of this flood upon less-mobile animals, such as reptiles and amphibians, was undoubtedly devastating, as their observed populations were significantly less in succeeding months.
Most other animals were observed to prosper during 2013 and 2014. During this time the frequency and count of both Bighorn Sheep and Mule Deer sightings increased in 2013, with five Bighorn lambs observed in Late Spring. No Bighorn lambs were observed or recorded in 2014, however.
• In 2015, the El Niño episode arrived with the greatest total yearly rainfall in four years. It was a year of relative plenty in terms of both food and water for all animals, big and small. Bighorn sightings increased with up to 16 individuals observed at one time, 5 of which were lambs. Mule Deer sightings were also up in frequency and count number. Small animals such as Rabbit (both Cottontail and Jackrabbit), Gray Fox, and Field Mice appeared to be much more abundant than in previous years. By the end of the year the Gray Fox population obviously had boomed, based on the amount of scat observed around the Casitas. The chipmunk population, however, was noted as having greatly declined by the end of 2015. Mr. and Mrs. Fox? Most likely.
When all of these various observations are considered together, it is clear that the climatic impact of the La Nada to El Niño transition upon plant and animal populations and the overall food chain during the cyclical transition from the 2012 drought to abundant precipitation in 2015 is definitely mirrored in the observed cycles of plant and animal population and reproduction variability. Some of these cyclical changes are obvious, others only suggested. What is certain, however, is that the overall ecology of the Bear Creek Nature Preserve provides a unique opportunity to observe first-hand the eternal cycles of Nature on a micro-scale for those who have the patience to observe, study and learn.
El Niño Winter of 2015-16. Fresh snow on the Mogollon Range in the Gila Wilderness, 10 miles northwest of the Casitas
FALL ENCHANTMENT IN THE GILA RIVER COUNTRY OF SOUTHWEST NEW MEXICO
Color, Light and Shadow Amongst the Floodplain Cottonwoods and Sycamores
Cottonwoods in Peak Fall color on Bear Creek in front of Casitas de Gila, looking north to Turtle Rock and Gila Wilderness beyond
In like form, about five miles north of the Casitas, within the Upper Box of the Gila River floodplain in the Gila National Forest, golden Cottonwoods arch into a deepening cobalt sky
On the Bear Creek floodplain below the Casitas, a grove of mature Cottonwoods catch the last rays of the setting Sun
Each year between the last two weeks of October and the first two weeks in November, visitors to Casitas de Gila Guesthouses are treated to the annual visual feast of color, light, and shadow along the floodplains of Bear Creek in front of the Casitas and at the nearby Gila River Riparian Preserve in the Gila National Forest.
In early morning light a small Velvet Ash in peak color casts long shadows beneath a towering Cottonwood on the Bear Creek floodplain below the Casitas
Looking down from the Casitas to the Bear Creek floodplain, deepening shadows gradually extinguish the light on the Cottonwoods and Sycamores ablaze in the last rays of the setting Sun
By Late October and Early November, the bright cerulean-blue skies of Summer are in transition to the deeper cobalt blues of Winter as the Sun arcs ever closer to the southern horizon. At this time the deep verdant greens of the dense riverine forest of Cottonwood, Sycamore, Willow, Ash, and Walnut are transformed into an evolving kaleidoscopic display of varying shades and tones of yellow, orange, red, brown, and purple as each of the species responds in its own way to the increasingly colder nighttime rivers of air that flow down into the canyons from the lofty mountain peaks of the Gila Wilderness to the north.
Late afternoon on Bear Creek, just upstream from the cliffs, November 11, 2014
Early morning on Bear Creek, just upstream from the cliffs, November 12, 2015
Depending on the year, the time of transition from first coloring to that final blaze of glory for each of the species can be prolonged or remarkably all-too-short depending on the vagaries of temperature, precipitation, wind, and controlling weather systems. This year the change was gradual and prolonged in response to a strong El Niño weather pattern dominating over the southwest, bringing milder temperatures and above-normal precipitation.
Late afternoon in the Upper Box of the Gila River, November 18, 2015; this is the exact same scene as photo on left, but one week later, and what a difference! By this date the leaves of the Cottonwoods and Sycamores are now at their peak
Late afternoon in the Upper Box of the Gila River, November 11, 2015; at this date the Cottonwoods and Sycamores are about halfway to reaching full color
One of the greatest joys of living surrounded by nature at the Casitas is the opportunity to visit and observe the same sites along Bear Creek and the Gila River on a frequent daily basis throughout the year and at different times of the day. Typically, the changes are slow, the change measured in weeks. However, come Fall and the coloring of the leaves, the changes are measured in days, especially towards the end of this month-long process. At this time the rate of change gradually accelerates to literally overnight transformation as Mother Nature completes her annual tapestry in color and signs it with an artistic flourish.
Looking east down the trail leading into Bear Creek Canyon below the Casitas on an early November afternoon; North and South Peak in the background. The white rock at the top of the cliffs directly above the top of the big Cottonwood is a large boulder of welded ash flow tuff, most likely placed there as a way-marker by the Apaches who traveled Bear Creek frequently.
Cottonwoods (Populus fremontii) are typically the dominant floodplain tree along Southwest New Mexico rivers and creeks. When their fall colors are at their peak, Bear Creek Canyon and the nearby Gila River Valley are literally transformed into rivers of gold. Taking a quiet walk within a mature grove of floodplain Cottonwoods on a warm afternoon at this time of year is to experience the essence of the Old Southwest, of times long ago when most of these river and creek valleys served as the primary trails and early roadways for the peoples of the Prehistoric and Pioneer Southwest. To pause and sit beneath one of these ancient Cottonwoods in the pervading silence will only heighten the experience … listen to the wind rustling high above in the upper branches; watch as the golden leaves spiral down to coat the canyon floor, their trunks reflecting in the still waters of the creek. Remain there for a longer time and perhaps the snapping of twigs will herald the approach of a trio of young Mule Deer, or possibly a furtive Bobcat on its way for a drink at the creek …
Cottonwood trunks reflecting in Bear Creek near the cliffs
Cottonwoods and Sycamores at the peak of Fall color on the Gila River floodplain in the Upper Box of the Gila; it is said that Watson Mountain in the background was a favorite stronghold of the Apache Chief Geronimo
Be assured that Mangas Coloradas, Geronimo, Victorio, Naiche, and the other Apache chiefs and their people passed where you sit on such an afternoon not all that long ago, for this was their homeland … the heart of Apacheria. And a few hundred years before the Apache, the Mogollon People were harvesting their crops of maize, squash, and beans on the first terrace above the floodplain, perhaps just across the stream from you. It is reported that for some people, their presence is still sensed here.
A magnificent ancient Sycamore on the Gila River floodplain in the Upper Box of the Gila; it is highly likely that Geronimo passed near this tree on his way upstream to his Watson Mountain stronghold
Once the Cottonwoods pass their peak of color, the Sycamores (Platanus wrightii) then emerge in striking visual accent and counterpoint from the mass of Cottonwood Gold, their russet-red star-shaped leaves and bone-white trunks and limbs set against the cobalt blue sky. For the photographer or landscape painter the sycamores are a special delight, particularly when their reddish leaves and white branches are reflected in the waters of the passing stream.
Two young Sycamores in peak Fall foliage on Bear Creek floodplain, November 18, 2015; note the tall Cottonwoods in background with golden leaves only remaining in uppermost branches at 50 to 60 feet, their lower leaves having turned and fallen earlier due to the much colder air flowing down the canyon at floodplain level
Large and small Sycamore leaves and a few Willow leaves with a bright green accent of watercress in a quiet pool along Bear Creek
Another flood-battered Sycamore in Elliot Canyon off Lower Little Dry Creek; note the height of battering on trunk on right, and the 3+ foot red rhyolite boulder wedged in between trunks. Sycamores are indeed the Warrior Giants of the floodplain forest.
A magnificent old and flood-battered Sycamore in Elliot Canyon off Lower Little Dry Creek
On some creeks, such as the lower reaches of Little Dry Creek a few miles upstream from its junction with the San Francisco River, Sycamores are the dominant floodplain tree, replacing most, if not all, of the Cottonwoods. The reason for this change is readily discerned in the gnarled and battered appearance of their trunks and lower branches. For where Sycamores are found to dominate, one quickly observes that these are high gradient, high energy creeks; creeks that are often the scene of raging floods and flash floods that stem from Springtime melting snows and Summer Monsoon thunderstorms in the nearby soaring mountains.
Torrential floods transport large volumes of coarse sediment and gravel. Often they carry boulders as big as small cars that crash into the Sycamores, gouging big holes in their trunks, and occasionally washing or tearing away all of their roots, causing them to fall. But many Sycamores can stand this perennial onslaught of Nature and grow to great size and age. Sycamores are much tougher and harder than Cottonwoods, which, even if by chance were to germinate and start growing here in these rocky canyons during a cycle of years of less severe flooding, would be quickly eliminated when the big floods occur.
Closeup of Warrior Giant Sycamore in process of digesting rhyolite boulders!
Frequently, one of these ancient and gnarled Sycamores will be observed growing around and beginning to encapsulate one of these huge flood-carried boulders. Often it appears as if the tree is in the process of digesting the boulder. Oh yes, these deep canyon Sycamores are without a doubt the Warrior Giants of the floodplain forest, and they proudly display their battle scars for all who choose to pass here as proof of their prowess.
A beautiful Velvet Ash in a drywash near the Casitas in full Fall foliage
Along the banks of calmer creeks, such as Bear Creak, a variety of Willows (Salix sp.), Velvet Ash (Fraxinus velutina), and Arizona Walnut (Juglans major) grow to more modest size in comparison to the Cottonwoods and Sycamores. These smaller shrubs and trees present a variety of colors from yellow to orange and red to purple which provide both visual harmony and counterpoint accents to the larger and taller Cottonwoods and Sycamores. These trees almost always color and lose their leaves earlier because of their closeness to the floodplain floor where the cold nighttime air flowing down the canyons is often 10 to 15 degrees colder than the upper branches of the floodplain Cottonwoods and Sycamores.
FALL ENCHANTMENT IN SOME SPECIAL PLACES IN THE GILA RIVER COUNTRY OF SOUTHWEST NEW MEXICO, NOVEMBER 2015
Where the Ancient Ones Once Tread: Floodplain Cottonwoods in the Upper Box of the Gila
Fall in the Upper Box of the Gila. Looking upstream at the junction of Mogollon Creek and the Gila River; Watson Mountain in the background
Over time, as one becomes familiar with the various segments of a particular creek or river, one eventually will come to recognize some “special places” — unique places where the balance and harmony of Nature’s landscape is perfect in every aspect. These are the uncommon places for which the Naturalist, photographer, or landscape painter blindly seek, but instantly know when encountered — places that cannot be summoned or set up, but, at that moment, just are.
Looking downstream, Sycamores in the Upper Box of the Gila River, November 11, 2015
Looking downstream, Sycamores in the Upper Box of the Gila River, November 18, 2015
Floodplain Sycamore, Upper Box of the Gila River, November 18, 2015
A few of these places have an extended timelessness in which their specialness prevails and can be savored slowly again and again; however, most do not. No, for most of such places, this ineffable specialness is fleeting, often measured in mere minutes as the play of light and shadow transforms the common into a brief perception of the Divine. These are the true treasures of Nature, and in Southwest New Mexico during those few weeks of Fall Enchantment from Late October to Mid November is when they are most likely to be found … and they wait for you here every year.
A late Fall evening in the Upper Box of the Gila River, November 18, 2015