|Location||Ross Lake National Recreation Area, Whatcom County, Washington, United States|
|Basin countries||United States|
|Surface elevation||1,201 feet (366 m)|
Diablo Lake is a reservoir in the North Cascade mountains of northern Washington state, United States. Created by Diablo Dam, the lake is located between Ross Lake and Gorge Lake on the Skagit River at an elevation of 1,201 feet (366 m) above sea level. Diablo Lake is part of the Skagit River Hydroelectric Project and managed by Seattle City Light. Diablo Lake Trail, designated a National Recreation Trail in 1981, runs for 3.80 miles (6.12 km) along the lake's northern shore.
The lake holds rainbow, coastal cutthroat, brook, and the federally threatened bull trout. It is a popular recreational spot for kayakers and canoeists. The unique, intense turquoise hue of the lake's water is attributed to the surrounding glaciers that grind rocks into a fine powder that is carried into the lake through creeks. That fine powder, also called glacial flour, stays suspended in the lake, giving the water its brilliant color.
- U.S. Geological Survey Geographic Names Information System: Diablo Lake
- "Diablo Lake Trail". American Trails. 2013-04-23. Retrieved 2014-08-14.
- Media related to Diablo Lake at Wikimedia Commons
- National Park Service website for Ross Lake National Recreation Area
- Seattle City Light, Diablo Lake Adventure