Diaz Lake was named for the Diaz family, who established a ranch here after brothers Rafael and Eleuterio Diaz emigrated from Chile in the 1860's. They owned and operated a successful cattle ranch until the land was sold to the City of Los Angeles Dept of Water and Power. Always a wetland, Diaz Lake was formed by the massive earthquake in the Owens Valley on March 26, 1872, when the ground below the lake dropped 16 to 20 feet and a new spring opened, causing water to fill the lowland. In a cooperative effort, DWP now leases the lake and surrounding area to Inyo County, which developed and currently maintains this popular campground and recreation area.