Amphitheater Mountain is located in the Lewis Range

Lewis Range

The Lewis Range is a mountain range located in the Rocky Mountains of northern Montana, U.S. and extreme southern Alberta, Canada. Formed by the Lewis Overthrust beginning 170 million years ago, an enormous slab of Precambrian rocks 3 miles thick, wide and long faulted and slid over newer...

, Glacier National Park

Glacier National Park (US)

While exploring the Marias River in 1806, the Lewis and Clark Expedition came within of the area that is now the park. A series of explorations after 1850 helped to shape the understanding of the area that later became the park...

 in the U.S. state

U.S. state

A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of Montana

Montana

Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...

. Amphitheater Mountain is a descriptive name given to the peak because of its resemblance to the Greek Amphitheater. The mountain's Blackfoot

Blackfoot

The Blackfoot Confederacy or Niitsítapi is the collective name of three First Nations in Alberta and one Native American tribe in Montana....

 name is Three Horns or Niuóxkai-ozkina for a Blackfoot warrior who captured a Nez Perce woman as was able to live happily ever after. The mountain has also been named Whalen Mountain for a former park ranger.