HARRISON — The Western Foothills Land Trust has acquired a conservation easement for 690 acres of working forestland within the Crooked River Watershed.

Lee Dassler of the Foothills Land Trust said the easement is the largest in its history and an important forestland protection with the watershed.

The easement was granted by landowners Mary and John Watkins on Nov. 21. It will protect 1.2 miles of shoreline along the Crooked River, more than 9,906 feet of Russell Brook (a landlocked salmon and trout fisheries resource) and 32.6 acres of wetlands, according to a statement released by Dassler.

“Prohibiting subdivision and protecting working forest and agricultural lands, the easement will also help to maintain forest-related jobs in western Maine,” Dassler said.

According to Dassler, the Watkinses purchased the historic Weston Farm in 1973 and added adjoining forestlands in 2006. The protected property, which is recognized in Harrison’s Comprehensive Plan as well as in the recently completed Lake Region Greenprint, is the largest contiguous single-ownership parcel in Harrison, she said.

Several years ago Paul Hunt of the Portland Water District told about 50 people during a meeting of area landowners on conservation easements that the Crooked River was linked to the purity of Maine’s largest public water source, Sebago Lake. He said Sebago’s status was slowly declining, along with the condition of all but the northern-most portion of the Crooked River.

A recent U.S. Fish and Wildlife Gulf of Maine habitat analysis identified the Watkins parcel as supporting important habitat for 36 of 91 USFWS priority trust species and provides particularly high value habitat, for 12 of those 36 species.

The Crooked River supports one of only four known indigenous populations of landlocked Atlantic salmon in Maine bringing to the river international notoriety from anglers seeking this type of fishing experience and researchers seeking to restore salmon populations throughout the world.

In May, a survey was begun to focus not only on the river banks but also on the entire watershed. Crooked River’s watershed encompasses approximately 120 square miles.

The Western Foothills Land Trust is an active member of the Upland Headwaters Alliance, a regional collaboration of area conservation organizations in Western Maine working on landscape-scale projects. UHA’s current focus is the Crooked River Initiative, an effort to protect and conserve the forested Crooked River watershed, which is the primary surface water source of Sebago Lake, Portland Water District’s reservoir.

Honoring the generosity of the Watkinses’ donation and the significance of this easement toward the overall health of the Crooked River’s functions, the Portland Water District and the Casco Bay Estuary Program are jointly contributing $9,250 toward the project’s stewardship fund. PWD is contributing $6,750 and the Habitat Protection Committee of the Casco Bay Estuary Program voted to contribute $2,500.