Fall Creek Adventures is part of the Weiser Basin.

“During the Triassic Period the Weiser River Basin was the west coast of the North American continent. On the west side of the Weiser River Basin lies Sturgill Peak and Cuddy Mountain which separate the valley from Hells Canyon. These peaks were at one time volcanic islands in the Pacific Ocean and are considered part of the same formation of Pacific islands as the Seven Devils Mountains which belong to the Seven Devils Volcanic Rocks” (page 17)

This document is a Master’s Thesis on the Weiser Basin.  It describes the indigenous people who lived here, geology, history of names, etc

This 1945 document has description of the people, lifestyle and landscape written by people alive in 1911.

This link shows the native American tribe boundaries.  You can zoom in and see where Fall Creek Adventures sits ….in the Cayuse, Umatilla and Walla Walla tribes and next to the Nez Pierce lands