Backcountry ski trip hit by avalanche led by tour outfit offering mountain adventures globally

The group of 15 was on a three-day trek organized by Blackbird Mountain Guides into pristine backcountry wilderness near Frog Lake in California's Sierra Nevada mountains near Lake Tahoe.

Skiers carried in their own food and overnighted in huts situated at 7,600 feet (3,415 meters).

“If you’ve booked the Frog Lake Huts in Truckee, trust our guides to elevate your trip to the next level,” the business said on its website, advertising the trip. “We’ll navigate in and out of the huts, manage the risks, and find the best terrain and snow quality for you and your group!”

On Tuesday, the group was trapped by an avalanche. Six skiers were rescued after sheltering in place for hours as crews battled blizzard conditions. Nine remain missing.

Blackbird Mountain Guides said in a statement that it was coordinating with authorities on the rescue operation.

It said the group, including four guides, was returning to the trailhead when the avalanche occurred.

The company, with offices in California and Washington state, offers mountaineering and backcountry ski trips across the U.S. West Coast as well as in Europe and Japan. The tour outfit also offers safety courses like wilderness skills and first aid.

The rugged terrain where the skiers are missing had been closed to the public for a century before the Truckee Donner Land Trust bought it and opened the huts, which are outfitted with basic accommodations such as sleeping pads, gas stoves and flush toilets.

The tour was rated for intermediate-to-expert skiers who should be prepared to climb up to 2,500 vertical feet (760 meters) throughout the course of a day, according to the company’s website. Guides carry first aid kits and “wag bags” for human waste disposal, but participants must bring their own ski equipment and avalanche gear, including a beacon, shovel and probe.

“Generally our guides are able to find excellent backcountry snow conditions, but often we need to travel through difficult conditions to access the goods,” the website description said. “This requires riders to be adept with their backcountry touring skills and have a solid foundation of touring before the trip.”

An avalanche watch was issued early Sunday as a powerful winter storm moved into the state. The Sierra Avalanche Center issued a more severe avalanche warning for the Central Sierra Nevada, including the Greater Lake Tahoe region, starting at 5 a.m. Tuesday with large slides expected into Wednesday.

Rapidly accumulating snow piling on fragile snowpack layers, along with strong winds, contributed to the treacherous conditions.

The town of Soda Springs, near where the avalanche took place, recorded at least 30 inches (76 centimeters) of snow during a 24-hour period, according to the Soda Springs Mountain Resort.