Thayer Brook Preserve
Description
The 147-acre Thayer Brook Preserve contains sections of Thayer Brook and a large 60-acre beaver flowage with exceptional bird and wildlife values. The preserve includes a short segment of a regional snowmobile trail, as well as mountain biking, hiking, and cross-country skiing trails that integrate with the Libby Hill Forest.
Thayer Brook Preserve is part of a state-designated wildlife sanctuary that prohibits hunting and trapping but allows fishing. As a result, dogs must be on leash at all times.
92 Ramsdell Road, Gray
4+ mile trail network

More information
Thayer Brook Preserve's trails connect to the Libby Hills Forest trails network, creating even longer loops or hikes from Ramsdell Road. Please abide by rules and regulations set forth by Libby Hill Forest Trails. Parking near Gray-New Gloucester schools (Libby Hill Road) provide convenient access to those trails.
Parking: There is a fourteen-space trailhead parking lot at 92 Ramdsdell Road, Gray, ME. This parking lot is plowed during the winter. Parking also exists at Libby Hill Road.
The multi-use (hiking, biking, and more) Mill Trail begins at the Ramsdell Road trailhead. This trail has some large puddles and muddy sections, pending improvements. Except during mud season, it is suitable for bikes and hiking, but plan on skirting a large puddle or two. No ATV use is allowed.
The Ridge Runner Trail (0.6 miles) is a hiking trail (no motorized use) that departs from the Mill Trail and connects to the Outback Trail, which is a part of the Libby Hill trail system. Further to the north along the Mill Trail, the Upper Trail (0.5 miles) is a hiking trail that leads to additional trails in the Libby Hill trail system. The Connector Trail (0.1 mile) is an upper connector to the extended Ridge Runner Trail.
A 3.4-mile Round the Marsh Loop trip around the beaver marsh may be formed by utilizing the Ridge Runner, Upper, and Libby Hill Trails. Recommended route from the junction: Clockwise, starting and ending the loop at the junction of the Mill Trail and Ridge Runner. By going clockwise, you can take every single right turn (except left at the junction of Mill and Ridge Runner).
For a shorter 2.6-mile experience, follow the Mill Trail to the Ridge Runner Trail and then loop around the Outback Trail.
Accessibility: Trails are rocky and unsuitable for even the most adventuresome wheelchair users. Even the Mill Trail has rocks, slopes, and puddles that limit access for wheelchairs. Sections of the Ridge Runner Trail have bog bridges, as pictured below.

Thayer Brook Preserve is a component of the Libby Hill unfragmented habitat block. At 2,580 acres this is the 5th largest unfragmented habitat block (undeveloped forest) in Greater Portland. Along with Libby Hill Forest, the Thayer Brook Preserve is now one of the few protected lands within this undeveloped forest. Royal River Conservation Trust and Presumpscot Regional Land Trust are today prioritizing more work to conserve more of this undeveloped forest. Many years and considerable effort and focus by numerous individuals and organizations have brought us here.
Thayer Brook Preserve was established in 2022 and was acquired in part with funding from the Maine Outdoor Heritage Fund (MOHF), the Casco Bay Estuary Partnership (CBEP), and Land for Maine's Future (LMF).
- Preserve trails are open for biking, hiking, snowshoeing, and back-country skiing. Snowmobiling is permitted on the Mill Trail.
- Dogs are welcome but must be leashed at all times due to wildlife sensitivities unique to this parcel.
- There is no hunting or trapping on this property, due to the neighborhood’s designation by the Maine Legislature as a wildlife sanctuary (“the Gray Game Sanctuary”). Fishing is allowed.
- No camping, overnight parking, fires, or smoking.
- Please respect postings on private abutting land.
Royal River Conservation Trust protects and stewards properties, including Thayer Brook Preserve, located within the traditional homelands of the Wabanaki. We strive to ensure that our properties are inclusive and accessible and provide opportunities for healing, education, and respite.
Libby Hill was named after Daniel Libby (1742-1826) who was an early settler and one of the first members of the Town of Gray Select Board. His descendants donated the land which became Libby Hill Forest.
An 18th or early 19th Century very primitive stone boulder dam (breached) crosses Thayer Brook very near the Mill Trail crossing of Thayer Brook. The stone dam is parallel to the beaver dams which form the upstream marsh and ponds.
Thayer Brook Preserve
The 147-acre Thayer Brook Preserve contains sections of Thayer Brook and a large 60-acre beaver flowage with exceptional bird and wildlife values. The preserve includes a short segment of a regional snowmobile trail, as well as mountain biking, hiking, and cross-country skiing trails that integrate with the Libby Hill Forest.
Thayer Brook Preserve is part of a state-designated wildlife sanctuary that prohibits hunting and trapping but allows fishing. As a result, dogs must be on leash at all times.