Portland to Auburn. This segment covers the abandoned St. Lawrence and Atlantic railroad corridor, owned by the State of Maine. The first 1.5 miles is part of the Eastern Promenade park in Portland. The route connecting the Eastern Prom to the Roux Institute campus in East Deering, Portland, is part of an existing project and grant. Design and construction are set to occur in the coming years.
The remaining 24.8 miles of the state-owned corridor from Portland to Auburn was authorized as “an interim bicycle and pedestrian trail” in L.D. 30, passed by the Maine Legislature in 2025. Next comes engineering and design, trail construction, and eventually, maintenance and operation. There is already exciting progress. The Greater Portland Council of Governments (GPCOG) recently issued a regional trail plan, listing portions of the Casco Bay Trail that are within the GPCOG region as high-priority projects. We are also in conversation with municipalities along the corridor to create an interlocal management district to be a cohesive local partner for MaineDOT in next steps for creating the trail.
Lewiston to Brunswick. The proposed trail route is the Lewiston Lower Branch Rail Corridor. Lisbon—the midpoint—is already home to the fantastic 2.1-mile Paper Mill Trail. Close to the Paper Mill Trail is another 2.57 miles of the Lewiston Lower Branch corridor in Lisbon. The Rail Use Advisory Council process has been completed for this segment and recommended that an interim bicycle and pedestrian trail was the best use of the 2.57 miles in Lisbon.
The State of Maine also owns the rest of the approximately nine-mile segment in Topsham and Brunswick. According to a 2024 report, use of these tracks is limited to a small section in Brunswick used as a turn-around for the Amtrak Downeaster. Next steps include exploring authorization of an interim trail for this corridor and advocating for the MaineDOT Commissioner to support authorizing an interim trail on 2.57 miles of the Lewiston Lower Branch.
Finally, the portion from Lewiston to Lisbon is owned by CSX but not used by trains. A 2018 report found the corridor was “suitable and feasible for conversion to a recreational trail facility.” Next steps include working with the cities of Lewiston, Auburn, Lisbon, and the Lewiston-Auburn Railroad Corporation to pursue ownership and approval for use as a trail.
Connections in Auburn, Brunswick, and Freeport. The remainder of the loop has connections in Auburn, Brunswick, and Freeport at varying stages of creation. There has been exciting progress in Auburn to Reimagine Washington Street, which would connect Danville Junction (the end of the state-owned rail corridor) to downtown Auburn. The segment from Brunswick to Freeport is undergoing route identification. Finally, the sections from downtown Freeport to Yarmouth are included in GPCOG’s regional trail plan, numbered 12N and 07N. Next steps include completion of routing and pursuing grants to fund design and construction.
CASCO BAY TRAIL ALLIANCE 