There are about 20 on the Colorado but Hoover Dam is the largest.
Hoover Dam =)
Hoover Dam.
Grand Lake is natural, but Shadow Mountain Lake and Lake Granby are also a part of the Big Thompson Project and their dams are at over 8,000 feet above sea level.
There are six of them on the Colorado river. Glenn Canyon dam, Hoover dam, Davis dam, Parker dam, Palo Verde diversion dam and Imperial dam.