Montana The state's name is derived from the Spanish word montaña which means mountain is very descriptive of the western third of Montana which contains numerous mountain ranges. The major ranges are Absaroka, Beartooth, Big Horns, Bitterroots, Flatheads, Madison, Lewis and Sawtooth. Smaller island ranges are found throughout the state, for a total of 77 named ranges that are part of the Rocky Mountains. Within Montana are many national parks; monuments, forest and grasslands include Glacier National Park, the Little Bighorn Battlefield National Monument, and Yellowstone National Park. Grasslands national parks located east of the western mountain ranges offer the visitor a view of the wild prairies crossed by Lewis and Clark – The Corps of Discovery. The Missouri River headwaters are located in the western mountains following the width of the state. Little Big Horn National Military Park is located in Crow Agency. Major industries throughout the state are agriculture, ranching and cereal grain farming, oil, gas, coal and hard rock mining, lumber, and tourism.