Derrick Cave, a lava tube in remote Lake County, Oregon, formed when a lava stream crusted over and later drained, leaving a hollow passage that helped create much of the Devils Garden lava bed. About 1,200 feet long, the cave includes a large chamber known as the Big Room, lava flow lines, lavacicles, and seasonal ice formations. Named for pioneer rancher H. E. Derrick, it served settlers as a cool summer gathering place and later figured in World War II and Cold War shelter planning, as well as NASA research in the 1960s. It is also an important bat habitat and protected sensitive cave environment.