From the Boston ChannelTV/5

A Newton doctor was one of two climbers who died Thursday when they fell several thousand feet on Mt. McKinley in Alaska.

Dr. John Mislow, 39, and Dr. Andrew Swanson, 36, of, Minneapolis, were roped together at the time of the fall, according to the National Park Service.

A team saw the pair fall between the 16,500-foot elevation on the Messner Couloir and its base at 14,500 feet.

It was not clear if the men were ascending or descending at the time of the fall.

Three skiers in the vicinity were first to respond to the climbers, who were located about 30 minutes away from the 14,200-foot camp.

A team of four volunteer NPS rangers, including an emergency room nurse and two medics, followed close behind and confirmed that the two men had died in the fall.

Officials said the two men began an ascent of the West Rib route on May 30, and their climbing registration forms did not specify a particular descent route.

Mislow and Swanson were both experienced mountaineers, according to park officials.

In 2000, Denali National Park and Preserve presented the two men with the Denali Pro Award, an honor recognizing the highest standards in the sport for safety, self-sufficiency, and assisting fellow mountaineers.

Situated in between the West Rib and the West Buttress routes, the Messner Couloir is a steep, hourglass-shaped snow gully that drops from near Archdeacon’s Tower at 19,000 feet down to the 14,200-foot basin.

With a 40- to 50-degree snow and ice slope, the Messner Couloir is an occasional advanced ski descent route, but is rarely descended on foot or ascended.