Allagash, located at the mouth of the Allagash River, is located in Aroostook County, Maine. Organized on September 28, 1885 as a plantation, it incorporated as a town on January 31, 1966, and has the most land area of any minor civil division in Maine at 135.6 square miles.
Near the end of Maine Route 161, the economy of Allagash is based in guide services and small stores with provisions for hunting and camping expeditions, although some farms remain, including one with a small herd of buffalo.