Mountaineering rangers were working Thursday evening on a bid to rescue climbers scattered high on Mt. McKinley in Denali National Park following an accident in which a guide and three climbers tumbled down a section of the mountain near the summit.

According to a release from the park, the four were descending from the summit ridge of the mountain either late Wednesday or early Thursday when they fell. One of the clients broke a leg in the fall, the release said.

The guide apparently directed the other two clients to head down to McKinley's the 17,200-foot "high camp" while treating the injured individual.

The park release said the guide helped the client with the broken leg down to a flat area at 19,500 feet known as the "Football Field" and placed him in a bivy sack, or light sleeping bag, before continuing alone on down to the 17,200-foot camp. When the guide reached that camp at 3:45 a.m. Thursday another climbing team camped there was able to use a satellite phone to call for help. They then tended to the guide's injuries, which ranged from frostbitten hands and feet as well as a possible broken rib sustained in another fall on his way down, the release said.

The other two clients, however, were not at the 17,200-foot camp when the guide arrived, the park release said.

"One of these two clients was spotted several hours later descending to high camp on the lower portion of the slope known as the 'Autobahn,'" the release said. "Members of the team at the 17,200-foot camp went out and assisted the client, who also had frostbitten hands and feet, back to camp.  The remaining uninjured client was last seen near Zebra Rocks at 18,300 feet, just above Denali Pass."

At 8 a.m. Thursday an HC-130 aircraft from the Alaska Air National Guard's 211th Rescue Squadron headed to the mountain to look for the injured and missing climbers, the release said.

"By mid-morning, two para-rescuemen from the 212th Rescue Squadron personnel on board the HC-130 spotted the client with the broken leg at 19,500-feet. The individual was observed waving to the aircraft," the release said. "The other client that was last seen at 18,300 feet was possibly spotted above Denali Pass, although the pararescuemen were unable to confirm movement or verify it was the client in question."

While visibility was good high on the mountain Thursday, winds were gusting to 70 mph and temperatures ranged from -13 degrees Fahrenheit to -31 degrees Fahrenheit at the 17,200-foot elevation, the park reported.

"Denali National Park’s high altitude A-Star B3 helicopter departed Talkeetna at 10:45 a.m. for the Kahiltna Basecamp to stage for a rescue once winds subsided.  While waiting for the high elevation winds to calm, the A-Star B3 helicopter with NPS rangers on board evacuated a different guided client who had been treated for frostbite at the 14,200-foot medical tent," the release said. "This client, a member of the same expedition as the climbers involved in the fall near the summit ridge, had descended with another guide earlier in the day on Wednesday due to symptoms of frostbite."

Park offidials said a Thursday evening rescue mission was being planned if weather conditions allowed.

As of Thursday, there were 275 climbers on Mt. McKinley, the majority of which were climbing the West Buttress route.