Group Tour Led by Gary Larson, facility operations manager with the Cold Regions Research and Engineering Laboratory, a tour group walks through the U.S. Army Corps of Engineers Permafrost Tunnel on Sept. 12, 2019. Larson pointed out parts of the tunnel significant in research of permafrost and how it relates to climate change. The tour transported the group to a time dating back 40,000 years. SHARE IMAGE: Download Image: Full Size (1.53 MB) Photo By: Daniel Nelson, Army VIRIN: 190912-A-ZW424-1009M.JPG Photo Gallery