Montana is a state in the northwestern United States of America, bordering North Dakota, South Dakota, Wyoming, Idaho and the Canadian province of Alberta. The state is best known for its impressive and diverse landscape, ranging from the Rocky Mountains to the Great Plains. Montana is also known as "Big Sky Country" because of its wide open spaces and impressive skies. The state's economy is based primarily on agriculture, mining and tourism. Montana attractions and landmarks include Glacier National Park, known for its spectacular alpine scenery, crystal clear lakes and abundant wildlife, and Yellowstone National Park, located partly in Montana and considered the world's first national park. Little Bighorn Battlefield National Monument commemorates the famous Battle of Little Bighorn between Native Americans and the U.S. Army. Montana also offers numerous opportunities for outdoor activities such as hiking, fishing, skiing, and whitewater rafting.