Lake Easton State Park, State park in Kittitas County, United States

Lake Easton State Park covers 697 acres in the eastern foothills of the Cascade Range, northwest of the settlement of Easton and 24 km east of Snoqualmie Pass. Its 7.3 km of shoreline border Lake Easton, a 111-hectare reservoir on the Yakima River held back by the 20 m high, 579 m long Easton Diversion Dam. Parts of the park remain old-growth forest of Douglas fir, western red cedar and western hemlock.

The Easton Diversion Dam, a 20 m high and 579 m long concrete gravity dam on the Yakima River, was completed in 1928 by the Bureau of Reclamation as part of the Yakima Project to irrigate the Yakima Valley, creating Lake Easton. The land for the park was bought by the state in five parcels between 1961 and 1991 for a total of 1,435,809 US dollars. The former Milwaukee Road rail line on the south shore is now part of Iron Horse State Park.

The park draws visitors year-round for outdoor recreation: swimmers and boaters enjoy the water in summer months, while winter snow brings cross-country skiers to the trails. Locals and travelers alike gather here to spend time outdoors and experience the mountain landscape.

The campground stays open all year and has more than 130 sites. A boat ramp, a six-metre dock and a swimming area sit on the lakeshore. Nine kilometres of paths serve hikers in summer and cross-country skiers in winter; the former Milwaukee Road rail bed runs along the lake's south side.

The former Milwaukee Road rail line along the lake's south shore is now part of Iron Horse State Park and serves as a hiking trail. The Easton Diversion Dam, a concrete gravity dam 20 m high and 579 m long, was completed in 1928 by the Bureau of Reclamation for the Yakima Project.