The Flaming Geyser State Park is located on the Green River in southwestern King County, Washington, near the city of Black Diamond. The park was named for a flame which burned 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. Both "geysers" can be found along a short hike, though as of 2016 the flaming geyser is no longer lit due to depletion of its methane source.