- the chief mountain system in North America, extending from central New Mexico to N Alaska. Highest peak, Mount McKinley, 20,300 feet (6187 meters).
- the chief mountain system of W North America, extending from British Columbia to New Mexico: forms the Continental Divide. Highest peak: Mount Elbert, 4399 m (14 431 ft). Mount McKinley (6194 m (20 320 ft)), in the Alaska Range, is not strictly part of the Rocky Mountains