Photos highlighting Libby Dam’s construction era and ID buttons collected by Papa Whitmarsh, maternal grandfather to Tana Wilson, natural resource manager at Libby Dam. The Army Corps began construction of Libby Dam in 1966 and completed the structure in 1972. The operating project is a straight-axis, concrete, gravity structure solidly anchored in bedrock. It was constructed with 7.6 million tons of concrete and holds back the water of the Kootenai River with its own massive weight. (Photo courtesy Tana Wilson)