The Flaming Geyser State Park is located on the Green River in southwestern King County, Washington, near the city of Black Diamond. The park is so named for a flame which burns through a concrete basin, fueled by a methane gas pocket 1,000 feet below the surface. When the pocket was discovered by prospective coal miners in the early 1900s, the test hole hit gas and saltwater, shooting water and flames 25 feet into the air. The same methane pocket seeps gas through a mud hole to create the "Bubbling Geyser" nearby.