Two snowmobile drivers were killed when they triggered an avalanche and were buried in the snow for nearly an hour, Alaska State Troopers said.

The two were driving their snowmobiles Friday in the backcountry near Turnagain Pass, about 70 miles (115 kilometers) south of Anchorage, when the avalanche occurred, Troopers spokeswoman Beth Ipsen said.

They were buried for about 45 minutes before being located. Troopers initially reported that three people had died in the avalanche, but the third person was recovered, evaluated by medical professionals at the scene and released, Ipsen said.

One snowmobiler was pulled from the slide, and snow was removed from the face of the other, but CPR efforts weren't successful, she said.

The victims' identities are being withheld until next of kin are notified.

The other three snowmobilers in the six-person party were accounted for. It wasn't immediately clear if they attempted resuscitation efforts, Ipsen said.

The remote location of the slide on the back side of a mountain hampered communication with troopers at the scene. Officials did not immediately have other information about the slide, including the depth of the snow.

The Chugach National Forest Avalanche Information Center reported 11 inches (28 centimeters) of new snow fell in a two-day period. That left the snowpack depth at 94 inches (239 centimeters) at a Turnagain Pass weather station, located at 1,800 feet (550 meters).

Officials had warned that avalanche danger would be high this weekend in south-central Alaska.

The avalanche information center had warned that natural avalanches were possible and huge snow slides triggered by humans were probable.

Troopers have encouraged backcountry recreationalists to travel in groups, pack provisions and safety gear and be aware of possible dangers in the snowpack.

With the latest deaths, avalanches have killed at least 32 people across the West since Dec. 2, according to the U.S. Forest Service National Avalanche Center. The two were the first recorded deaths in Alaska this winter.