Mount Katahdin is the highest mountain in the U.S. state of Maine at 5,269 feet. Named Katahdin, which means "Great Mountain", by the Penobscot Native Americans, it is within Northeast Piscataquis, Piscataquis County, and is the centerpiece of Baxter State Park. It is a steep, tall massif formed from a granite intrusion weathered to the surface. The flora and faun…Mount Katahdin is the highest mountain in the U.S. state of Maine at 5,269 feet. Named Katahdin, which means "Great Mountain", by the Penobscot Native Americans, it is within Northeast Piscataquis, Piscataquis County, and is the centerpiece of Baxter State Park. It is a steep, tall massif formed from a granite intrusion weathered to the surface. The flora and fauna on the mountain are typical of those found in northern New England, with the summit hosting fragile and endangered alpine tundra.