The Washington Department of Transportation is asking drivers to be prepared when traveling over mountain passes after numerous closures over the weekend.

The first major storms of the winter season led to requirements such as chains or snow tires on Stevens, Blewett and Snoqualmie passes.

Some of the closures on Snoqualmie and Blewett passes were caused by multiple spinouts and crashes involving vehicles that we not properly chained, according to WSDOT.

The agency is urging drivers to pay attention to road conditions and tire requirements before traveling over the passes.

WSDOT also says its crew are actively plowing the mountain passes, and is urging drivers to give plows space on the roadway.

"WE want to emphasize that people give the plows space to move," said WSDOT spokesperson Lauran Loebsack. "Don't try to pass a plow. They'll get out of your way when they have pull-offs."

WSDOT said Snoqualmie Pass received more 1.5 feet of snow over the weekend, with more expected overnight Monday morning. Blewett and Stevens pass also received 1,5 feet of snow. All three passes have two feet of snow accumulation.

State Route 971 was also closed Sunday morning near Lake Chelan because if a down tree on the roadway.

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