Horse Lava Tube System

The Horse Lava Tube System (or Horse system) is a series of lava tubes within Deschutes County, Oregon, of the United States. The system starts within the Deschutes National Forest on the northern flank of Newberry Volcano and heads north into and near the city of Bend. The lava flow that created the Horse system is also referred to as the Horse Cave lobe and it filled the ancient channel of the Deschutes River which at that time flowed around the east side of Pilot Butte.