Bonfire Shelter

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

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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.

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.

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 rear wall of nearby Skiles Shelter.

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 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.

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 Skiles Shelter were used along with hand-held grinding stones (called manos) to pulverize seeds and nuts.

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.

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. 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.

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.

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. 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 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.

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.

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 to the right half way up the canyon wall.

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 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.

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.

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'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.