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Prehistoric Texas Main

A Tour of Mile Canyon

By Steve Black

One spring morning I had the privilege of joining a small group on a tour of Mile Canyon. Leading the tour were landowner Jack Skiles and archeologist Elton Prewitt, who was on the excavation crew during the original 1963-64 excavations at Bonfire Shelter. There aren't many ways into and out of Mile Canyon and all of them require strenuous climbing. We start at the top of a ravine that plunges into the canyon. At the goat pens at the top of the trail Elton warns us to watch for "dog cactus," a small ball of wicked thorns that tends to fasten itself to your pants leg or boot heel. As you walk along, the dog cactus can get flipped upwards becoming attached to the seat of your pants! Elton relates a painful occasion in 1963 when this happened to him at the end of a long hot day. Unaware, he sat down hard on a rear bench seat of a Carryall and instantly dented the roof with his head. I laughed at the story, but kept an eye out for dog cactus.

As we walked along, Jack Skiles told me that his late father, Guy Skiles, had purchased Mile Canyon and the immediate surroundings in 1944. As a young man Guy Skiles had dug into many of the caves and shelters in the area in search of interesting Indian artifacts. But rather than sell these items off, as many diggers did, Guy created his own private museum. As he grew older, Guy Skiles learned to appreciate how much more can be learned through a scientific approach and befriended many of the archeologists who have worked in the region. During the Skiles family's tenure, no one has dug into the rockshelters of Mile Canyon except for scientists. Jack Skiles inherited his father's curiosity about the past and went to college and graduate school where he earned a Master's degree in botany. While a high school science teacher, Jack received a grant from the National Science Foundation that allowed him to attend the University of Texas for one year and bone up on other sciences including geology and archeology. While attending UT in 1961, Jack invited archeologists to come take a look at the cave on his property containing burned bison bones.

 

Thirty years later, we headed down the ravine toward the same cave, Bonfire Shelter.

We enter Mile Canyon through a steep ravine following goat trails.

Click images to enlarge  

We enter Mile Canyon through a steep ravine following goat trails.

Reaching the Mile Canyon proper, we head downstream along an almost imperceptible rock ledge favored by sure-footed goats.

Reaching the Mile Canyon proper, we head downstream along an almost imperceptible rock ledge favored by sure-footed goats.

Our first destination is Kelly Cave, a modest-sized rockshelter visible in this photo as a dark hole.

Our first destination is Kelley Cave, a modest-sized rockshelter visible in this photo as a dark hole. An adjacent rockshelter, Skiles Shelter, lies just below and to the right of Kelley Cave.

Kelly Cave was badly disturbed by relic collectors in the 1920s and 1930s. The surviving deposits contain many fragments of plant fibers, animal bones, charcoal, stone-tool-making debris, and spent cooking rocks. These traces show that the rockshelter was lived in countless times over thousands of years.

Kelley Cave was first tested by archaeologists E. B. Sayles and J. Charles Kelley in 1932.  Uncontrolled digging in the late 1930s did considerable damage. The surviving deposits contain many fragments of plant fibers, animal bones, charcoal, stone-tool-making debris, and spent cooking rocks. These traces show that the rockshelter was lived in countless times over thousands of years.

Elton Prewitt and Jack Skiles look at faded pictographs - painted images -- on the protected wall of Kelly Cave.

Elton Prewitt and Jack Skiles look at faded pictographs—painted images—on the protected rear wall of nearby Skiles Shelter.

Close up of pictographs at Kelly Cave. These paintings were created over 3,500 years ago. Most are thought to be symbolic expressions of the sacred rituals and beliefs of Lower Pecos peoples.

Close up of pictographs at Skiles Shelter. These paintings were created over 3,500 years ago. Most are thought to be symbolic expressions of the sacred rituals and beliefs of Lower Pecos peoples.

The upper surface of this limestone boulder in Kelly Cave is worn slick from being rubbed by countless people, possibly during leather working. The sharp grooves may have resulted from dulling the edge of chipped-stone tools during tool making.

The upper surface of this limestone boulder in Skiles Shelter is worn slick from being rubbed by countless people, possibly during leather or fiber working. The sharp grooves may have resulted from dulling the edge of chipped-stone tools during tool making.

Here the group looks for the small dark green "VV numbers" - Val Verde County site numbers -- which archeologists painted in each cave and rockshelter they recorded.

During the late 1950s and early 1960s, archeologists from The University of Texas visited Skiles Shelter and hundreds of other sites in the area prior to the damming of Amistad Reservoir. Here the group looks for the small dark green "V V numbers" —Val Verde County site numbers—which archeologists painted in each cave and rockshelter they recorded. During the survey work, small teams of archeologists spent many months combing the canyons for sites and they sometimes lost track of which shelters they had visited. The V V numbers helped avoid confusion.

These shallow bowl-shaped depressions in the bedrock along one wall at Kelly Cave were used along with hand-held grinding stones (called manos) to pulverize seeds and nuts.

These shallow bowl-shaped depressions in the bedrock along one wall at Skiles Shelter were used along with hand-held grinding stones (called manos) to pulverize seeds and nuts.

Leaving Kelly Cave, we head upstream past where we entered Mile Canyon.

Leaving Skiles Shelter, we head upstream past where we entered Mile Canyon. The large boulders you see here may look like permanent fixtures, but once or twice a century raging floodwaters move even house-sized boulders. Each catastrophic flood changes the topography of the canyon, spring-fed pools become choked with gravels, new springs emerge, and walnut trees are ripped out. Such events would have impacted the lives of the Lower Pecos hunter-gatherers and caused shifts in settlement patterns that may have lasted for several generations.

The winter and early spring of 2001 were unusually wet in the Lower Pecos. Weeks after the last rain water still stands in numerous small pools. By the middle of summer, water will be scarce and only available at a few large pools and permanent springs.

The winter and early spring of 2001 were unusually wet in the Lower Pecos. Weeks after the last rain, water still stands in numerous small pools. By the middle of summer, water will be scarce and only available at a few large pools and permanent springs.

Because of the ample winter rains, this Little Black Walnut tree will bear a large crop of tasty and nutritious little nuts.

Because of the ample winter rains, this Texas Black Walnut tree will bear a large crop of tasty and nutritious little nuts. Walnuts are one of many resources that are only available in certain times of the year and in certain places in the landscape. In the Lower Pecos region, walnuts only grow in the protected canyons where their roots can find water.

Close up of green walnuts. These will grow and slowly ripen over the spring and summer, becoming edible in early fall.

Close up of green walnuts. These will grow and slowly ripen over the spring and summer, becoming edible in early fall. Good things may come in small packages, but wild walnuts are tough nuts to crack and require special pulverizing techniques such as the use of the shallow bedrock depressions in the caves.

Midway up the canyon we come to Eagle Cave, the biggest rockshelter in the canyon and one of the largest in the region. This natural erosional feature was sculpted by water and wind over an immense stretch of time. When prehistoric peoples first entered the area, at least 13,500 years ago, they began using natural shelters like Eagle Cave.

Midway up the canyon we come to Eagle Cave, the biggest rockshelter in the canyon and one of the largest in the region. This natural erosional feature was sculpted by water and wind over an immense stretch of time. When prehistoric peoples first entered the area, at least 13,500 years ago, they began using natural shelters like Eagle Cave.

Eagle Cave is filled with massive trash deposits representing countless everyday activities in the lives of prehistoric hunter-gatherers. Called "midden" deposits by archeologists, these gray ashy layers are filled with spent cooking rocks, animal bone, plant remains, broken stone tools and all sorts of other artifacts and natural objects hauled into the shelter by its inhabitants.

Eagle Cave is filled with massive trash deposits representing countless everyday activities in the lives of prehistoric hunter-gatherers. Called "midden" deposits by archeologists, these gray ashy layers are filled with spent cooking rocks, animal bone, plant remains, broken stone tools and all sorts of other artifacts and natural objects hauled into the shelter by its inhabitants.

This young man stands in the bottom of the main excavation trench dug by explorers from the Witte Museum in 1936.

Archeologist Rob Thrift stands in the bottom of the main excavation trench dug by explorers from the Witte Museum in 1936 and reopened and excavated deeper in 1963 by Univerisity of Texas reseachers. The trench has slumped in, but it still gives you a good idea of how thick the deposits are. The lowest cultural layers in Eagle Cave have never been reached.

This photo shows what is left of the upper layers of the cave as exposed in the old trench walls. The dark brown layers are perfectly preserved plant fibers: grass, leaves, stalks, and all sorts of plant debris cast aside more than a thousand years ago.

This photo shows what is left of the upper layers of the cave as exposed in the old trench walls. The dark brown layers are perfectly preserved plant fibers: grass, leaves, stalks, and all sorts of plant debris cast aside more than a thousand years ago. The dry climate and protected shelters preserve things that are never found at open campsites.

The walls of Eagle Cave were once covered with hundreds of pictographs, most of which were created over 3,500 years ago. Most of these have faded with time or are obscured by the dust kicked up during the 1936 excavations.

The walls of Eagle Cave were once covered with hundreds of pictographs, most of which were created over 3,500 years ago. Most of these have faded with time or are obscured by the dust kicked up during the 1936 and 1963 excavations.

Close up of some of the pictographs in Eagle Cave that are still visible. Today these pictographs are known mainly from the fine copies made by Forest Kirkland in the 1920s and 1930s.

Close up of some of the pictographs in Eagle Cave that are still visible. Today these pictographs are known mainly from the fine copies made by Forest Kirkland in the 1920s and 1930s.

A wooden pestle may have been used to pound mesquite beans or similar resources into flour in this bedrock mortar hole at Eagle Cave.

A wooden pestle may have been used to pound mesquite beans or similar resources into flour in this bedrock mortar hole at Eagle Cave.

View up Mile Canyon from Eagle Cave. Bonfire Shelter lies just around the bend.

View up Mile Canyon from Eagle Cave. Bonfire Shelter lies just around the bend.

Upstream from Eagle Cave, Mile Canyon continues to narrow and in places we must squeeze between narrow rocky passages.

Upstream from Eagle Cave, Mile Canyon continues to narrow and in places we must squeeze through narrow rocky passages.

The group stops to rest below Bonfire Shelter. The shelter is just visible on the right.

The group stops to rest below Bonfire Shelter. The shelter is just visible to the right half way up the canyon wall.

Elton Prewitt on the precarious "trail" used by 1963-64 excavation crew to approach Bonfire Shelter. The shelter is visible on the upper left.

Elton Prewitt on the precarious "trail" used by 1963-64 excavation crew to approach and exit Bonfire Shelter. The shelter is visible in the background. Just below Elton is a small pool of water that came to be known as "Bic Pen Springs" because of all the yellow ballpoint pens that fell out of Dave Dibble's pocket as he crawled up this steep slope and collected there during the field season.

Elton Prewitt stands below the south end of Bonfire Shelter and recounts the excavation of Bone Bed 3. Behind him is the talus cone below the notch in the cliff through which hundreds of bison fell.

Elton Prewitt stands below the south end of Bonfire Shelter and recounts the excavation of Bone Bed 3. Behind him is the talus cone below the notch in the cliff through which hundreds of bison fell.

Elton Prewitt points out areas where more protective material is needed to Jack Skiles.

Elton Prewitt points out areas where more protective material is needed to Jack Skiles. In 1990, Elton and a crew of volunteers wrapped the talus cone in burlap bags topped with orange plastic mesh to help retard erosion. Runoff from the occasional heavy rain drains into the cave and erodes Bone Bed 3.

Close up view of the burned bison bone fragments that continue to erode from Bone Bed 3, the Late Archaic jump episode(s) that occurred about 800 B.C.

Close up view of the burned bison bone fragments that continue to erode from Bone Bed 3, the Late Archaic jump episode(s) that occurred about 800 B.C.

View from south end of the shelter to the central area where the main excavations have been carried out. The wooden walkway helps protect the still-open excavation holes from caving in.

View from the talus cone at the south end of the shelter to the central area where the main excavations were carried out. The wooden walkway helps protect the still-open excavation holes from caving in.

View of the excavation walls near the rear of the shelter. Notice the stratified deposits of cave dust and roof spall. Bone Bed 2 lies just above the wooden ladder.

View of the excavation walls near the rear of the shelter. Notice the stratified deposits of cave dust and roof spall. Bone Bed 2 lies just above the wooden ladder.

Elton points out to Jack places where the main excavation walls have recently slumped.

Elton points out to Jack places where the main excavation walls have recently slumped. The two are planning on shoring up the walls to protect the remaining deposits. But first, Jack wants archeologists to find the bottom of Bonfire Shelter.

Jack Skiles holds the welded rebar he used to probe below the deepest excavations at Bonfire Shelter.

Jack Skiles holds the welded rebar he used to probe below the deepest excavations at Bonfire Shelter. Jack's probe revealed that there are at least 10 feet of gravel deposits at the bottom of the shelter below the deepest known bone layers.

View of central area of Bonfire Shelter from the north. The massive rock pile (fallen roof blocks) upon which most the bison fell is visible on the right.

View of central area of Bonfire Shelter from the north. The massive rock pile (fallen roof blocks) upon which most the bison fell is visible on the right.