Katahdin (kətäˈdĭn) [key], mountain, 5,267 ft (1,605 m) high, between branches of the Penobscot River in N central Maine; highest point in Maine. The peak and the beautifully wooded, lake-dotted territory surrounding it constitute Baxter State Park, the gift of Gov. Percival P. Baxter in 1931. Katahdin Mt. is the northern terminus of the Appalachian Trail.