Summer Lake is a large, shallow, alkali lake in Lake County, Oregon, United States located 5 miles (8 km) south of the small, unincorporated community of Summer Lake, Oregon. At high water it is about 15 miles (24 km) long and 5 miles (8 km) wide, and supports a wide variety of birds and other wildlife in its marshes. The lake was named by explorer John C. Fremont on his expedition into Central Oregon in 1843. During the summer this lake can reduce noticeable and a large dry lake bed left in its place. Plumes of Summer Lake dust, lifted by winds of up to 60 miles per hour (97 km/h), are thought to be responsible for "dirty rain" that fell on February 6, 2015, across parts of three U.S. states: Oregon, Washington, and Idaho. Scientists at Washington State University concluded that an unusual combination of weather systems carried the dust up to 500 miles (800 km) north and northeast, where it mixed with rain, which turned "milky". Chalky residue coated cars and windows in Hermiston, Spokane, and at least 13 other cities.