King County’s Moss Lake Natural Area, east of Lake Joy, will close to the public for more than two weeks starting Sept. 11, as crews remove a culvert along a small stream in advance of installing a replacement bridge there next year.

The culvert removal project will block access to the majority of the trail system that winds through the natural area, which features a rare sphagnum moss bog, forested wetlands, and other habitat features.

Heavy dump truck traffic should also be expected along the Moss Lake Natural Area’s access road, and the gate to the parking lot will remain closed for the duration of the project.

Crews will reestablish public access to the site as soon as the old culvert is removed. Workers will monitor water elevations throughout the winter and into early spring to determine the proper height for a permanent bridge structure.

The 372-acre Moss Lake Natural Area is located 5 miles southeast of Duvall and about 3-½ miles northeast of Carnation. It receives a modest amount of public use from hikers, equestrians and mountain bikers.