[1]: 3-113 Discovery of a Clovis point projectile along the bottom of Cle Elum Reservoir in 1984, south of Waptus Lake, leads to suggestions that the region may have been a site of the residence of Indigenous peoples of the Northwest Plateau with Clovis culture,[5]: 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.

[8] Bordering the Pacific Crest Trail, hiking to Waptus Lake is a popular activity.

The follows a valley floor with old-growth forest, frequently crossing small snowmelt creeks.