The Tulsa District, U.S. Army Corps of Engineers will close traffic to the State Highway 151 bridge over Keystone Dam August 22 to September 1 to study the rock abutments and materials used to construct the dam. Keystone Dam was constructed between 1957 to 1964. Access to W. Wekiwa Road on the north side of the dam, and the off road vehicle area on the south side of the dam will be available for visitors. Keystone Dam will continue to operate as normal as the closure only affects the bridge.