Reports of the avalanche reached the sheriff's office shortly after noon and ski patrol officials had reached the group by 12:50 p.m.
Stevens Pass is one of the most popular outdoor recreation destinations on the Northwest, particularly for skiing, snowboarding and backpackers.
About two hours south at Snoqualomi Pass, a snowboarder was killed after another avalanche struck Sunday and he went over a cliff. Rescue video taken earlier this month shows a man being rescued when an avalanche buried him next to his snowmobile.
There have now been 13 avalanche deaths this winter season, according to the Colorado Avalanche Information Center. Experts have said that a weak base layer of snow caused by a dry winter has lead to the dangerous conditions.