Crack in the Ground is a volcanic fissure over two miles long and up to 70 feet deep in Northern Lake County, Oregon. The eruptions from the Four Craters Lava Field were accompanied by a slight sinking of the older rock surface, forming a shallow, graben-like structure about 3 kilometers wide and extending to the south into an old lake basin. Crack-in-the-Ground marks the western edge of this small, volcano-tectonic depression. The crack is the result of a tension fracture along a hingeline produced by the draping of Green Mountain lava flows over the edge of upthrown side of the concealed fault zone. This recreation area is on BLM lands and a great place to photograph and have fun.