Lake Pateros, Reservoir on the Columbia River in Washington, United States

Lake Pateros is a large, deep reservoir on the Columbia River in Washington that stretches upstream from the dam. The lake is surrounded by open land with gentle hills and offers wide views across the water, with two boat launches for access and home to trout and steelhead fish.

The lake was created in 1967 when Wells Dam was built, backing up the Columbia River and flooding the original town of Pateros. The reservoir now controls water flow and generates hydroelectric power as part of a larger dam system in the region.

The reservoir has carried many names: Butler Lake, Chief Long Jim Lake, Fort Okanogan Lake and Lake Azwell are documented variants, alongside the present name taken from the town of Pateros on its shore. The Columbia here lies almost entirely in Douglas and Okanogan counties, with the dam touching Chelan County.

The reservoir runs from Wells Dam upstream to Chief Joseph Dam, with Pateros and Brewster as the main towns on its shores. The dam itself lies partly in Chelan County, while the water sits almost entirely in Douglas and Okanogan counties. Access is by road along the Columbia, and the water is a reservoir, so levels follow dam operations rather than a natural cycle.

The reservoir has carried many names: Butler Lake, Chief Long Jim Lake, Fort Okanogan Lake and Lake Azwell among them. These variants survive in older maps and records, so the same stretch of the Columbia can appear under a different label depending on the map's date.