Thayer Brook Preserve

Thayer Brook Preserve in Gray is 147 acres owned and managed by Royal River Conservation Trust. The Preserve abuts Libby Hill Forest trails and contains sections of Thayer Brook and a large beaver flowage with exceptional bird & wildlife values. The Preserve supports a short segment of a regional snowmobile as well as mountain bike and hiking trails integrated with Libby Hill Forest.

Dogs must be on leash (noting the large numbers of deer and wildfowl.) No hunting or trapping, noting state statutes governing the state wildlife sanctuary. Fishing is allowed.

More Information


New April 2024! Preserve and trail map (easily printed 8.5 x 11 PDF)

(The preserve map PDF is georeferenced and can be downloaded into the Avenza Maps app for interactive use on a smartphone).

Regional context map (easily printed 8.5 x 11 PDF)

Libby Hill Forest trail maps (overlapping with RRCT’s Thayer Brook Preserve)

Trails, Trailheads and Accessibility

Thayer Brook Preserve was created in late March 2022. Certain new trails (see maps) were opened in July 2022. Please respect that more trails and more signage will be works-in-progress during 2024. See “Maps” above for most-recent maps showing new trails.

Trailhead parking lot development at 92 Ramdsdell Road — fourteen spaces — is now complete (May 2023). Parking also exists at Libby Hill Road.

The multi-use Mill Trail (snowmobile, biking, hiking, more) enters the preserve near the 92 Ramsdell Road trailhead, with pedestrian and bicycle access from the trailhead parking lot. The Mill Trail and its bridges have some large puddles and safety issues, pending improvements. Except during mud season, the Mill Trail is suitable for bikes and hiking but plan on skirting a large puddle or two. Or three.

3.4-Mile ‘Round the Marsh Loop Trail (Lollipop) from Ramsdell Road: See maps. The Ridge Runner and Upper Trails (no motorized uses) leave the Mill Trail (motorized) at various locations creating a 3.4-mile round trip lollipop loop around the large beaver marsh. Recommended route from the junction: Clockwise, starting and ending the loop at the junction of Mill and Ridge Runner. By going clockwise, you can easily take every single right turn (except left at the junction of Mill and Ridge Runner, the beginning of the lollipop). If you go counter-clockwise, take every single left (except right at the junction of Mill and Ridge Runner, the beginning of the lollipop).

2.6-Mile Loop from Ramsdell Road: See maps. Mill, Ridge Runner, and Outback Trails create a shorter loop, including the marsh’s viewpoint.

Thayer Brook Preserve trails (see map) for biking, running, and and hiking are also connected to the Libby Hill 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.

Libby Hill Trails publishes these trip descriptions for 4-mile or 4.5-mile loops integrating Libby Hill and Thayer Brook Trails. All Trails and other apps are also starting to public Thayer Brook Preserve hikes as trails are developed and improved.

Accessibility: Trails are rocky and unsuitable for even the most adventuresome wheelchair users. Even the ATV trail has rocks, slopes, and puddles that limit access for wheelchairs.

Management Plan

RRCT’s interim management plan is designed to guide initial management actions and priorities at Thayer Brook Preserve. This document allows our cooperators, neighbors, members, and friends to establish clear expectations about what opportunities are (and are not) provided at this particular preserve.

Download a PDF of the interim management plan. In 2024 we are updating this plan; check in with us if you’d like to see draft revisions.

What’s next: Consultation with neighbors, clubs

RRCT created a Preserve Outreach Group to gather local input and resources to get the preserve created, open the new parking lot, and create and improve trails. The group also monitors sensitive habitat supporting Maine DIFW.

Volunteer Steve McPike leads this group. If you would like to get involved with this group, Steve is looking for more members. Please contact him at SteveMcPike (at) Gmail (dot) com if you have an interest in getting involved at any level or any questions on the new preserve. Steve is also available to speak to local groups on the new preserve and RRCT conservation plan.

You can keep up on news and new trails by joining the RRCT email list and following RRCT on Facebook.

RRCT will have future sessions with RRCT Trail Crew to continue to get to know the property and its neighbors better. Join us! Get involved!

Rules, Regulations and Hunting

  • Fishing is allowed.
  • 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”). See 12 MRSA 12706 et seq.
  • Snowmobile usage is welcome on one designated trail — the Mill Trail.
  • ATV use was discontinued in 2023 by MBPL.
  • Preserve trails are open for biking, hiking, snowshoeing, and back-country skiing.
  • Please be judicious with trail activities during spring thaw and excessively wet or saturated periods. Please help us avoid trail closures due to trail damage or rutting.
  • Dogs are welcome on RRCT’s Thayer Brook Preserve but must be leashed, due to wildlife sensitivities unique to this parcel. More information on the pet policy for the adjacent Libby Hill Forest trail network can be found here.
  • Please respect various postings on private abutting land.
  • Smoking is prohibited at all RRCT preserves.

RRCT & You: Updates, Alerts and Cautions

LIMITED TRAIL DEVELOPMENT: This preserve was created in late March 2022. Please respect that trails and signage are a work in progress during 2024.

RRCT & You: RRCT relies heavily on volunteers and help from trail users like you. You may know more recent information about trail and preserve conditions than we do. We invite you to be a thoughtful steward by acting as a respectful visitor, adhering to posted rules, and following Leave No Trace practices. RRCT’s small staff and volunteer Trail Crew is able to inspect and maintain RRCT preserves infrequently; we ask you to report to us any issues you observe that you cannot address yourself, and especially to update us on any safety or public safety issues. Please help us on your visits with litter, pet waste, and minor trail issues. We also invite any information on needed or suggested updates to this webpage. Reach out in any way, most simply with an email to

RESPONSIBLE PET OWNERSHIP: Our preserves provide valuable access for pets and pet owners. We are always concerned by pet waste left behind, and by dogs not controlled by their owners. Please help us create a culture of respect and responsibility. Thayer Brook Preserve has exceptionally large populations of white-tail deer and water fowl. The adjacent trail system requires leashes due to heavily used trail systems. RRCT requires that dogs be leashed.

NEIGHBORS’ POSTINGS: Please respect various postings on private abutting land. Please let us know if you are a neighbor with concerns about the evolving interface between our land and your land.

Conservation History

The Thayer Brook Preserve is a component of the Libby Hill unfragmented habitat block. At 2580 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 a large number of individuals and organizations have brought us here.

1973 – Sylvia Dow, a descendant of one of Gray’s earliest settlers Daniel Libby, leaves 70 acres to the Town of Gray as a recreation space. Use of the land as a picnic area was brief and soon suspended.

1999 – Gray Town Council creates a committee to revive Libby Hill as a recreation area and recruits volunteers build 5 miles of cross country ski trails, opened in 2001.

2002 – Gray Community Endowment (GCE), a non-profit to provide a donation option is formed by Carl Holmquist with a volunteer Board of Directors including Steve McPike and Ann Gass. The original town committee reorganizes as the Friends of Libby Hill and works actively and collaboratively with GCE.

2003 – Will and Richard Libbey, descendants of Daniel Libby, donate two woodlots to GCE in memory of their father, Harold Libbey.

2005 – Harold Libbey Trail, providing access to Thayer Brook, completed.

March 2022 — Royal River Conservation Trust acquires Thayer Brook Preserve property from members of the Durgin and Rogers families — all descendants of Evelyn “Binnie” Morrill Durgin. Scroll below for the “History” tab for more information on the Durgin and Morrill families. RRCT works closely alongside the Presumpscot Regional Land Trust on this and other key Gray projects. RRCT acquires the parcels using bridge financing from an anonymous family and transactional funding from the Casco Bay Estuary Partnership and Maine Outdoor Heritage Fund. In 2023 RRCT secures conservation funding to repay the bridge financing, from sources including the Land for Maine’s Future program and USFWS wetland funding (NAWCA).

In 2020 and 2022, the Town of Gray Comprehensive Plan and Town of Gray Open Space Plan designates this area a “critical rural area,” supporting the concept of future conservation.

Land conservation in Gray is a strategic priority for Royal River Conservation Trust, Presumpscot Regional Land Trust, Maine Farmland Trust, and the Town of Gray. For more information on RRCT’s approach and rationale for land conservation in Gray, see RRCT’s 2022 Conservation Plan.

History & Historic Interpretation

Abenaki: Prior to colonization of Maine by the British and the French, the land currently known as the Thayer Brook Preserve was occupied and stewarded by the Abenaki, one of the sovereign nations forming the Wabanaki Confederacy. This Maine Historical Society website celebrates the heritage and modern strength of the Wabanaki. Thayer Brook drains to the Presumpscot River; River Voices: Perspectives on the Presumpscot (Sanford, Plumley et al, 2020) includes Abenaki voices and history.

New Boston & Gray (colonization): Beginning in 1735, British (Massachusetts) land speculators began laying claim to the land that is now Gray, calling it New Boston. Thayer Brook Preserve flows to the Presumpscot River; the British had earlier begun damming the Presumpscot, destroying fish habitat and passage. In 1734, Wabanaki Chief Polin continued a long-standing high profile dispute with the Governor of Massachusetts regarding the dams, famously paddling to Boston in 1739 with pomp. The Maine Historical Society site (link above) narrates this failed diplomatic effort.

Daniel Libby (1742-1826): Libby Hill was named after an earlier settler (1764) and one of the first members (1778) of the Select Board of Gray. His descendants later donated land which became Libby Hill Forest.

Goff’s Mill Pond (water wheel): 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. Deeds refer the the pond as “Goff’s Mill Pond.” Members of the Goff family settled Ramsdell Road in the eighteenth century. William Goff (1759-1777) died at age 18 in the American Revolution at Germantown, after fighting at Lexington and Bunker Hill.

We don’t know what generation of Goffs built the dam, or whether they settled the area before William. This article in the Press Herald describes some of the history of dams in the area, including the profound re-shaping of the Little Sebago outlet. Dams were used by the earliest settlers in the 1700s. The American Revolution began an era of development of dams and mills. The Great Freshet in 1814 washed out many dams. We’ve found no evidence of a mill building or cellar hole near the dam that created Goff’s Mill Pond.

In 2022, Mrs. Rogers recalls that her family referred to the old dam as the “water wheel” site, presumably providing power for a small sawmill. The water wheel was affixed to cut stones immediately below the field stone dam.

Morrill and Durgin families: In 2022, RRCT acquired the land from members of the Durgin and Rogers families, all heirs or descendants of Evelyn Morrill Durgin (1920 to 2007) and her father Matthew Gardiner Morrill (1894 to 1972). M. Gardiner Morrill assembled the ownership of what is now Thayer Brook Preserve in 1931, 1944, 1949, and 1968. M. Gardiner Morrill’s grandfather was the honorable Matthew Churchill Morrill (1842 to 1926), who enlisted in the Second Maine Cavalry during the Civil War. He served in both the Maine House (1893) and the Maine Senate (three terms beginning 1895, 1905, 1921). He was the sponsor of legislation to prohibit carrying old soldiers to the poorhouse. Read here for a campaign letter-to-the-editor written by Matthew C. Morrill in 1920 describing his votes for Abraham Lincoln, and his role buying the right-of-way for the Portland and Lewiston Interurban Railroad which he felt was “one of the greatest assets belonging to the people of Maine.”

The Interurban started operation in 1914, and stopped operation in 1933; small portions of the Interurban rail bed in New Gloucester are now owned by RRCT and the Town of New Gloucester as a recreational trail. In Gray, some remains of the Interurban are privately owned and run through the Gray Meadows where the Interurban contains an ATV and snowmobile trail with beautiful views of the marsh and headwaters of the Pleasant River.

Historic maps and historic aerials: This file shows historic and modern aerial photos starting in 1940, and historic topo maps from 1894, showing what the neighborhood looked like before the Turnpike, before the school buildings, and more.

Natural Resources & Habitat

Thayer Brook drains to the Pleasant River which joins the Presumpscot River in Windham before heading to Casco Bay. Libby Hill forms the height of land that separates the Presumpscot and Royal River watersheds; the Gray-New Gloucester school campuses drain to the Royal River. Upstream from the Preserve, the Thayer Brook watershed is entirely developed and surrounded by more than 2000 aces of as-yet undeveloped (but not yet conserved) forests, creating one of the largest remaining habitat areas in greater Portland.

Along with undeveloped nearby streams and forests, Thayer Brook Preserve is part of a state-designated wildlife sanctuary (scores of privately-owned parcels in this neighborhood have this state designation) which prohibits hunting and trapping but allows fishing. As a result, the Preserve has exceptionally large populations of white-tailed deer and beavers. The Preserve is dominated by a large beaver marsh formed by more than six beaver dams, hosting enormous beaver lodges and large populations of birds. The beaver marsh (dam) was expanded significantly in 2010, flooding a section of forest; those dead trees today provide support for large bird nests built from beaver-chewed twigs and branches, protected from predators by the beaver pond.

Beyond the marsh, most of the acreage of the preserve is dominated by “glacial erratics.” Glacial erratics are enormous boulders left behind as glaciers melted more than 10,000 years ago. The challenging rocky terrain is one reason the Preserve has seen relatively little farming and no residential development over recent centuries.

On the road shoulders of Ramsdell Road, cut in half by Ramsdell Road near RRCT’s parking lot, a peatland bog supports high bush blueberries and beautiful Northern or Purple Pitcher Plants (Sarracenia purpurea) visible from the Ramsdell Road pavement. Peat and sphagnum in this wetland is measured to be four feet deep; peatlands are exceptional for their storage of carbon well beyond the levels of most forests and wetlands. We’ve noticed high counts of birds in this peatland — higher even than the bird count in the beaver marsh.

In the bog we’ve observed bogsuckers (aka American Woodcock, scolopax minor, timberdoodles). These quirky entertaining squatty wobbling birds are among the highlights of a Maine spring and summer. Read more.