Lava Beds National Monument years BP to 1,110 years BP. Some of the major Lava Flows within Lava Beds National Monument include the: Callahan Flow; Schonchin Flow; Mammoth Crater Flow; Modoc Crater Flow; and Devils Homestead Flow. Gillem Bluff, a fault scarp, was created as the region stretched and a block of earth dropped down along this fault (see Basin and Range Province). The tuff layer on top of Gillem Bluff is 2,000,000 years old, indicating the rock layers beneath are even older. The oldest lava flow from the Medicine Lake Volcano within the monument is the Basalt of Hovey Point, near Captain Jack's
Ice-marginal lava flow activity and erosion. In the late 1800s, a debris flow from the Barrier created a large boulder field which gave Rubble Creek its name. Conditions are so bad that the area directly below the lava damn is considered uninhabitable and dangerous to human life. Hoodoo Mountain A second example of ice-marginal lava flows can again be found in British Columbia, this time near the border of Alaska. The Hoodoo Mountain Volcano is located in Northwestern British Columbia The volcano formed underneath a glacier, making it a subglacial formation. The Hoodoo Mountain Volcano is a flat-topped stratovolcano as a result of