Developed and managed by the Town of Yarmouth, the West Side Trail is a multi-use trail for hikers and walkers, runners, and off-road single-track bicyclists that connects neighborhoods, office parks, preserves, and public beaches. Segments under construction are designed for commuter biking, family-friendly biking, and trekkers with less mobility. The trail is currently more than 10 miles round trip and is continuing to expand and improve each year toward a 12-mile round-trip goal (11.1 miles of trail footpath including various loops and spurs) in 2023. Much of the trail is under the cover of the tree canopy adjacent to the CMP power line corridor that the route follows. Visitors can expect to enjoy ravines, rocky bluffs, and vistas of Casco Bay and the Royal River estuary with an unexpected sense of remoteness, even while crossing more than a dozen neighborhood streets.

The West Side Trail was first conceived in 1988, in the Town of Yarmouth Public Access and Recreation Plan (PARP). The Royal River Conservation Trust is a strong supporter of this community-driven Town of Yarmouth project, along with the Rotary Club of Yarmouth, the National Park Service, Central Maine Power Company, Bicycle Coalition of Maine, and the Greater Portland chapter of the New England Mountain Bike Association. Significant funding has come from the Maine Bureau of Parks & Lands, Recreational Trail Program. The support of the Yarmouth Town Council and so many others helped move this nearly 30-year-old plan toward reality and planned completion in 2023.