Baker Mountain is an undeveloped, trail-less backcountry mountain in Beaver Cove, Piscataquis County, Maine, near Lily Bay, Elephant, and White Cap mountains. Its significance lies in how its slopes feed three separate drainage systems: eastward to the Pleasant, Piscataquis, and Penobscot rivers and Penobscot Bay; southwestward through brooks, ponds, streams, and Sebec Lake to the Sebec River; and northwestward into Moosehead Lake, the source of the Kennebec River and ultimately the Gulf of Maine. The mountain stands on 4,300 acres acquired by the Appalachian Mountain Club in 2015, and its southern slopes are part of the Katahdin Iron Works conservation property.