The Trust for Public Land says it has permanently protected Maine's Bald Mountain Pond and land around it.
The Appalachian Trail runs next to the pond, which is in Somerset County, about 15 miles southwest of Greenville.
The trust says more than 2,600 acres were purchased for just over $4 million from Weyerhaueuser. The funds came from a variety of federal and state programs, along with private contributions.
The acreage will be managed by the National Park Service as part of the Appalachian Trail Corridor in Maine.