UPDATE: Avalanches kill two teen snowshoers and a snowmobiler, blocks Highway 20

SNOQUALMIE PASS, Wash. (AP) - Authorities say two teenagers who went missing during a snowshoeing trip near Snoqualmie Pass were killed in an avalanche.   King County Sheriff's Sgt. Ryan Abbott says searcher found the boys, ages 17 and 18, just before noon Monday.

He says searchers believe they were killed in an avalanche while snowshoeing in a backcountry area near the Alpental ski area Sunday.  The boys' parents called 911 when they didn't return from a trip Sunday night.

Abbott says weather conditions and avalanche dangers prevented a search until Monday morning.

An avalanche killed a 32-year-old Seattle-area man who was snowmobiling with four friends near Stampede Pass.  The Kittitas County Sheriff's Office says Joseph Simenstad, from Issaquah, died Sunday afternoon in an avalanche that also buried his wife and others.  Five snowmobilers from Western Washington were eating lunch at the base of a slope in an area near Stampede Pass, about 60 miles southeast of Seattle, when the slope above them broke away.  The avalanche fully buried three of them, and partially covered the other two.  The sheriff's office says Simenstad suffered extensive injuries and couldn't be revived. His wife suffered minor injuries. Another man was unconscious when he was dug out but was revived.

Meanwhile, an avalanche has covered a section of SR20, blocking traffic in both directions and preventing several dozen people from leaving the area.  Transportation officials say a large snow slide Sunday covered State Route 20 east of Newhalem in Whatcom County.  Officials say about five dozen people are stuck behind the slide area, but all have access to food and housing.  WSDOT crews have started work to clear the  slide  bit the work is expected to take until at least Wednesday.

Sunday's snow slide covered an area about 11 miles west of where the highway closed for the winter.  Crews are reassessing the slide area Monday. Transportation officials don't have an estimate for when the road will re-open.  The highway is the northernmost route across the Cascade Mountain Range in northern Washington. The state closes a 37-mile section during the winter because of avalanche danger and snow conditions.