Mount Massive, Mountain peak in Sawatch Range, Colorado.

Mount Massive is a mountain in the Sawatch Range of the Rocky Mountains, in Lake County, Colorado, about 10.6 miles west-southwest of Leadville. Its summit ridge runs over 3 miles long and carries five summits above 14,000 feet, the highest at 14,428 feet, so the mountain holds more ground above 14,000 feet than any other in the contiguous 48 states. The photograph shows the long, nearly level crest, dark grey and brown rock with snow patches in the gullies, and lodgepole pine forest on the lower slopes.

Henry Gannett completed the first documented ascent of this mountain in 1873 during the Hayden Survey expedition. The climb was part of the broader scientific exploration of Colorado's high peaks during that era.

In Arapaho the Collegiate Range and Mount Massive share the name Hiwoxuu hookuhu'ee, "Elk's Head". The name is recorded in the Arapaho language alongside the English one, and the elongated, five-summit profile is what gave the mountain its English name as well.

The main route is a class 2 trail on the eastern face, 13.6 miles round trip with 4,500 feet of elevation gain; a class 2 route also follows the southwest slopes. Treeline sits just below 12,000 feet, so the upper section is open rock. Start early to be off the exposed ridge before afternoon storms.

During the Great Depression, backers of Mount Massive piled stones on the summit to raise its height above rival Mount Elbert, which is only 12 feet higher; Elbert supporters knocked the piles down. The summit ridge runs over 3 miles (4.8 km) long, with five summits all above 14,000 feet.