Two men were killed when they were struck by an avalanche in the north-central Rocky Mountains, authorities in Colorado said Sunday.

The pair were riding snowmobiles Saturday when a wave of snow hit them on the east face of Mount Epworth in Grand County, about 6 miles east of Winter Park, according to the Colorado Avalanche Information Center.

The avalanche was reported at about 2:15 p.m., and sheriff’s deputies, search-and-rescue crews, ski patrol members, and local good Samaritans immediately found one of the victims, a 58-year-old from northern Colorado, buried in snow, the Grand County Sheriff’s Office said.

They couldn’t revive him, and he was pronounced dead at the scene, the sheriff’s office said in a statement. The county coroner is expected to release the man’s identity later, it said.

The other rider couldn’t be located, and first responders had to stop the search as the weather got worse, the sheriff’s office said.

Rescuers, including members of the sheriff’s office, Grand County Search and Rescue, the Grand County EMS Mountain Medical Response Team, the Winter Park Ski Patrol, Flight for Life and the avalanche center, returned and discovered the remains of the second victim shortly before 11 a.m. Sunday, the sheriff’s office said.

The victim was identified only as a 52-year-old, with the coroner expected to release his name later. He wasn’t using an avalanche transceiver, making his recovery more difficult, officials said.

The avalanche center said the 58-year-old was found with the help of his transceiver, which is designed to transmit the locations of lost or buried mountain visitors.

The National Weather Service reported high temperatures in the area below 30 degrees, with overnight lows dipping into the single digits.

Sunday’s discovery means four people have died in Colorado avalanches since Dec. 26, according to avalanche center data.

“We encourage those recreating in our backcountry to regularly monitor the conditions and follow the advice of our avalanche professionals at Colorado Avalanche Information Center,” Sheriff Brett Schroetlin said in a statement.

On New Year’s Eve, a father and his adult son were backcountry skiing when an avalanche struck them near Breckenridge Ski Resort, about 65 miles south of Winter Park.

The father was able to dig himself out, according to the Summit County Rescue Group, but his son was buried, and his body was recovered roughly two hours later.

On Dec. 26, four backcountry riders, including skiers and snowboarders, were struck by an avalanche triggered unintentionally by a snowboarder near Berthoud Pass, about 55 miles west of Denver, the avalanche center said. Two were buried, and one of those two died, it said.

The avalanche center said the riders were a father, who died, and his three teenage sons. Officials later identified the father as Brian Bunnell, 44, of Lakewood, Colorado, NBC affiliate KUSA of Denver reported.

The Rocky Mountains have been dusted repeatedly by Pacific storms fueled by an atmospheric river of precipitation drawn from tropical climes. The avalanche center said another such front was expected Tuesday.

Snow can pile up in areas preferred by many backcountry skiers. Both of the fatal December avalanches occurred in areas that were easy to access, KUSA reported.

“Inside ski area boundaries, we have very dedicated ski patrols and snow safety teams that will work really hard to mitigate threats from avalanches inside ski area boundaries,” Brian Lazar, the deputy director of the avalanche center, told the station last month. “Just on the other side of that rope there is no one doing that work.”

Seven of the 20 people caught in avalanches during the 2021-22 season died, according to the avalanche center.