[2] Pete Lake is located in a prominent valley that comprises the most significant waterway to the Salmon La Sac region.

A discovery in 1984 of a Clovis point projectile leads to suggestions that the region may have been a site of the residence of Indigenous peoples of the Northwest Plateau with Clovis culture,[3]: 4-39, 4-40  perhaps of the Wenatchi People, one of the Confederated Tribes of the Colville Reservation and within the ceded lands of the Yakama Nation.

Archaeological surveying in the area shows no additional evidence from materials or engineering to confirm the discovery.

In the vicinity of the Salmon La Sac region lie prehistoric and early historic Native American sites including artifact scatter, petroglyphs, resource procurement areas, and seasonal salmon camps indicating that these may be associated with the Kittitas or other Bands and Tribes of the Yakama Nation.

The first 2.5 miles from Cooper Lake is a valley floor with old-growth forest, frequently crossing small snowmelt creeks.