In the 196Os, 78,458 acres of land adjacent to the GRTS, Gerstle River Expansion Area (GREA), was leased for use by the Arctic Test Board at Fort Greely. Prior to being leased to the Department of Defense (DoD), by the State of Alaska, and the Bureau of Land Management (BLM) in 1964, the land was an undeveloped wilderness area. During DoD ownership, three test grids, with support areas and command posts, were established at the expansion area. GREA was used as a test site for ordnance and chemical operations, field trials, and engineering analyses on agents and munitions.

From July 1965 to July 1967, GREA was used to statistically and dynamically test GB and VX filled 155mm munitions, VX filled 8-inch munitions, GB filled M55 rockets, and GB filled bomblets. Tests were also conducted to determine the types of weapons and munitions under different climatic conditions. These tests were carefully controlled and well documented. However, four GB filled 155mm rounds were not accounted for during the various test programs in the expansion area. In April 1970, the land lease permit for 13,719 acres of BLM property expired and the land was returned to BLM.

In June 1972, the lease for the remaining 64,829 acres was terminated and the land was returned to the State of Alaska. Prior to the lapse of this lease, a number of environmental cleanups were performed at the entire GRTS, with "Operation Cleanup Alaska" being the last one in 1971."

Associated Munitions:

CWM projectiles including 15mm GB and VX filled, 8-inch rounds, M55 rockets and GB fillled bomblets.

An Archives Search Report (ASR) was prepared in June 1994 by the USACE, St. Louis District. The ASR documented the current conditions and information available from the records of the post’s active period. No soil or groundwater sampling was conducted during this effort. A site characterization of the GREA was performed by the Huntsville Division, Corps of Engineers, in September 1994. The site characterization involved nonintrusive, visual and magnetometer investigations of seven sites in the GREA. The site investigation recommended further investigation for three areas.