Obsidian Boulders

We car camped a night at Obsidian Butte on the Salton Sea during our travels (we are now at Joshua Tree National Park). The place lives up to its name with obsidian (volcanic glass), often as huge boulders, everywhere. The result of this is that there is now limited room for sleeping, my wife having collected enough obsidian to furnish her own volcano. The water in the background is the Salton Sea, a sea formed in 1905 when the Colorado River overflowed and flooded the area.