Life in Montana's mountainous western area differs greatly from that on its eastern plains. Across the eastern half of the state stretch broad sections of the Great Plains, drained by the Missouri River, which originates in SW Montana, and by its tributaries, the Milk, the Marias, the Sun, and especially the Yellowstone. Much of Montana's western boundary is marked by the crest of the lofty Bitterroot Range, part of the Rocky Mts., which dominate the western section of the state and along which runs the Continental Divide. Montana's very name is derived from the Spanish word montaña, meaning mountain country.
Much of the fourth largest U.S. state is still sparsely populated country dominated by spectacular nature. High granite peaks, forests, lakes, and such wonders as those of Glacier National Park attract many visitors to Montana. Other places of interest include Little Bighorn Battlefield National Monument, Big Hole National Battlefield, and Grant-Kohrs Ranch National Historic Site (see National Parks and Monuments, table) and the National Bison Range, near Ravalli, where herds of buffalo may be seen. Strips of Yellowstone National Park, including the north and west entrances, are also in Montana, as are such Native American reservations as the Blackfoot, the Fort Belknap, the Fort Peck, and the Crow. Rushing mountain streams and numerous lakes bring fishing enthusiasts to the state, and the abundant wildlife—elk, deer, bear, moose, and waterfowl—attracts hunters. Mountain and ski resorts draw other vacationers. Helena is the capital, Billings and Great Falls the largest cities; other important cities include Missoula and Butte.