NEWHALEM — An avalanche has covered a section of rugged highway in northern Washington, 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. 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.