The King County Sheriff's Office says a female snowshoer who was rescued after an avalanche yesterday died.
Weather conditions in the area are too dangerous to continue the search for another missing person.
Initial reports said as many as three people were missing after the avalanches.
The King County Sheriff's Office says one avalanche, at Granite Mountain, carried three snowshoers about 1,000 feet.
The two men emerged from the snow, but their friend is still missing.
At another site at milepost 50, a group of about 12 people from Sammamish went out snowshoeing. At about the 4,800 foot level, an avalanche split the group in two.
Kay Seo, a woman that was part of the group, said her survival instincts kicked in.
"Horrible experience, fear, avalanche came down like water... water shape... so we held onto trees and we survived," she said.
Rescuers made contact with the larger group at about 6 p.m.
People familiar with the trail said it was very steep and dangerous in snowy conditions.
The avalanches occurred as heavy snow was falling in the Cascade Mountains east of Seattle.
The King County Sheriff's office says the weather conditions Sunday were too dangerous to continue search for the missing snowshoer.
Interstate 90 is not affected by the avalanches.