Grand Valley Diversion Dam, Mesa County, Colorado 39.189014 -108.281925 USA https://en.wikipedia.org/wiki/Grand_Valley_Diversion_Dam Grand Valley Diversion Dam https://goo.gl/maps/g9YvQRX5ZxDHLFnU9 Map of Grand Valley Diversion Dam A roller dam near Cameo that was constructed with large gates, the first and biggest installed in the United States to that point. Its construction made the Highline Canal Possible, and later, electrical generation. It was built between 1913 and 1916 and is now on the National Register of Historic Places yes yes