The Henry Mountains region in southeastern Utah is one of the classic areas in geology because of the study made there by Grove Karl Gilbert in 1875 and 1876. His report on the geology of the mountains was the first to recognize that intrusive bodies may deform their host rocks and the first to show clearly the significance of the evenly eroded plains, now known as pediments, at the foot of desert mountains.
The Henry Mountains with the surrounding structural basin is a rugged, dry, and sparsely settled region, a part of the Colorado Plateaus province. The natural obstacles of the region-the aridity and ruggedness-have kept it primitive. It has not been penetrated by modern methods of transportation and thus it persists as a roadless frontier. Even the Indians seem to have made little use of the region; explorers did not enter it until 1869 and settlements were not started until the eighties.