Arnold Lava Tube System

Arnold Lava Tube System
Location	Deschutes County, Oregon, USA
Geology	basalt of Lava Top Butte
Difficulty	Easy to Moderate
Access	Varied
Cave survey	Mostly Complete

The Arnold Lava Tube System (or Arnold system) is series of lava tubes in Deschutes County, Oregon, of the United States. It is located several miles southeast of the city of Bend. The system starts in the Deschutes National Forest on the northern flank of Newberry Volcano, heads northeast onto BLM land before finally terminating on private property near Horse Ridge. The system acted as a conduit for the lavas from Lava Top Butte that later fed the Badlands rootless shield. The lava flow that created the Arnold system is also referred to as the basalt of Lava Top Butte and is related to the Horse Cave lobe which is a lava flow that created the Horse Lava Tube System. The lava flows of Lava Top Butte, the Badlands, the Horse system, and the Arnold system all have a geologic age around 80,000 years old.

The system got its name from Ronald Greeley of NASA who named it during his study of lava tubes for the Oregon Department of Geology and Mineral Industries. He based it on one of the first discoveries in the system: Arnold Ice Cave. The cave was discovered by Americans as early as 1889 and referred to as the Crook County Ice Caves. Arnold Ice Cave was also the site of an early ice mining operation. The ice was sold to the city of Bend and relieved the ice market which was cornered by one of the early saloon keepers. At one time, a trench was chopped into the ice by Jim Anderson and Phil Coyner in the 1950s. They gained access to about a half mile of passage. Years later, after the ice mining had ceased, the cave filled back up with ice, and the inner passages in the cave proved to be inaccessible to exploration attempts. Many years later, in the early 1970s, Ronald Greeley, during his research on lava tubes, named one of the caves in the system. Deg Cave was named after the initials of Donald E. Gault, the Branch Chief for Planetology at NASA Ames Research Center.

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