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Ross Lake
Ross Lake · Whatcom County · Skagit Hydroelectric Project reservoir
A long reservoir behind Ross Dam fills the Skagit valley inside Ross Lake National Recreation Area, one of three lakes made by Seattle City Light.
Ross Lake sits on the Skagit River in Whatcom County, inside Ross Lake National Recreation Area. The park foundation document lists that unit at 116,798 acres. NPS boat-in camping pages treat the lake as a reservoir reached from the water, not from a lakeshore highway.
NPS says Ross, Diablo, and Gorge lakes were created by dams of the Skagit Hydroelectric Project, operated by Seattle City Light. Diablo Lake, just downstream, is the turquoise reservoir most visitors see from State Route 20. Ross Lake itself stretches north toward the Canadian border.
The recreation area is the developed corridor through the North Cascades complex. The sources below are the National Park Service record of the lake, the foundation document, and the Diablo Lake page.
- Geography & Geology
Sources (3)
government · Tier S
National Park ServiceBoat-in Camping
government · Tier S
National Park ServiceDiablo Lake
government · Tier S
National Park ServiceFoundation Document, North Cascades National Park Service Complex
Last reviewed: September 20, 2026
Keep wandering
nearby
Diablo LakeThe turquoise is not dye. It is rock, ground to flour by ice and held in a reservoir.
same park
North Cascades National ParkNPS calls this the most heavily glaciated area in the United States outside Alaska, with more than 300 glaciers on the high peaks.
nearby
Washington PassA 5,500-foot overlook on the North Cascades Highway looks across Liberty Bell, Early Winters Spires, and Kangaroo Ridge.