Above Benham Falls

More than 7,000 years ago a lava flow from Lava Butte dammed the Deschutes, creating a lake that extended many miles upstream. Over the centuries the water flowing over the relatively hard basalt of the lava flow sought an easier path. Eventually the river mades its way softer to the relatively softer andesite and ryolite from the Cascades and wore its way through. This is where the lava dam was breached.