Crews will begin clearing the slide Monday, and expect to complete the work by Wednesday, Whatcom County Parks and Recreation said Friday.
Recent snow, rain and ice saturated the soil, while freezing and thawing likely helped cause the slide.
The slide was minor but active, and park users are being asked to stay away.
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The popular trail, which is 3 miles one way, sits between Stewart Mountain and Lake Whatcom. It meanders through forest and then along the lake’s shores, providing views of surrounding hills, waterfalls and Douglas fir.
Stay updated by going online to co.whatcom.wa.us/2098/Lake-Whatcom-Park.