In which present day U.S. state did the Battle of the Little Bighorn take place?

The Battle of the Little Bighorn, known to the Lakota and other Plains Indians as the Battle of the Greasy Grass and also commonly referred to as Custer's Last Stand, was an armed engagement between combined forces of the Lakota, Northern Cheyenne, and Arapaho tribes and the 7th Cavalry Regiment of the United States Army. The battle, which resulted in the defeat of U.S. forces, was the most significant action of the Great Sioux War of 1876. It took place on June 25–26, 1876, along the Little Bighorn River in the Crow Indian Reservation in southeastern Montana Territory.

Montana is a state in the Northwestern United States. It is the fourth-largest in area, the 8th least populous, and the third-least densely populated of the 50 U.S. states. The western half of Montana contains numerous mountain ranges. Smaller island ranges are found throughout the state. In all, 77 named ranges are part of the Rocky Mountains. The eastern half of Montana is characterized by western prairie terrain and badlands. Montana is bordered by Idaho to the west, Wyoming to the south, North Dakota and South Dakota to the east, and the Canadian provinces of British Columbia, Alberta, and Saskatchewan to the north.