In January 1941, the Army began construction of the 30,617-acre Spencer Artillery Range as an annex of Camp Forrest. Intended as a firing range for heavy artillery, it was utilized by other units, including infantry. The 2nd Ranger Battalion practiced rappelling and bluff scaling here on the Rocky River Gulf. During the D-Day invasion, that same battalion scaled the bluffs at Point du Hoc near Omaha Beach in Normandy.