The area was prospected by the dinosaur hunter Charles Hazelius Sternberg in the summer of 1921.

[1] Sternberg collected the type specimen of Pentaceratops fenestratus, a ceratopsid dinosaur from the late Cretaceous Period, within the WSA.

Specimens from this area form a significant part of the vertebrate paleontology collection at the Museum of Evolution, University of Uppsala, Sweden.

The John D. Dingell, Jr. Conservation, Management, and Recreation Act, signed March 12, 2019, authorizes the establishment of the Ah-Shi-Sle-Pah Wilderness as a component of the National Wilderness Preservation System, protecting approximately 7,242 acres.

[3] Rock units within the Ah-Shi-Sle-Pah WSA include most of the upper Fruitland Formation (Fossil Forest Member) and lower part of the Kirtland Formation (Hunter Wash Member), both late Cretaceous in age.