By 1900 there were 220,000 cattle and 1.75 million sheep in the Rio Grande Basin. Since then, unpalatable plant species, such as Aristida spp. have become more common. This is the only excavated site of the Piro people who occupied this valley until early in the Spanish period. Most likely, the people fell victim to early slave traders and were either removed or fled in the mid to late 16th century. This shelter was apparently used during the summer when fields were planted here in Palo Duro Canyon.
Nearby middens contain maize cobs.
One or more major pueblos existed along the Rio Grande, about 10 km to the west, but were eventually dominated by Spanish settlements and massive sheep operations. Burn exclosures A two-way factorial experiment was established here to study the impacts of fire and antelope. Replicate plots are 900 m x 900 m in size to facilitate monitoring by remote sensing and to avoid artifacts of small plots. A recent reintroduction of prairie dogs to the Sevilleta by an honors undergraduate student focuses on the role of these mammals as keystone species that regulate species diversity. Canyon is nestled in the Great Nonconformity, where 1.3 billion years of earth history are conspicuously missing.