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, derived from the Spanish word montaña (mountain). Montana has several nicknames, none official, including: "The Treasure State" and "Big Sky Country", and slogans that include "Land of the Shining Mountains" and more recently, "The Last Best Place". The state ranks fourth in area, but 44th in population, and accordingly has the third-lowest population density in the United States. The economy is primarily based on services, with ranching, wheat farming, oil and coal mining in the east, and lumber, tourism, and hard rock mining in the west. Millions of tourists annually visit Glacier National Park, the Battle of Little Bighorn site, and three of the five entrances to Yellowstone National Park.