Territory that became part of Montana had been split off as part of the Washington Territory.) The boundary between the Washington Territory and Dakota Territory was the Continental Divide (as shown on the 1861 map); however, the boundary between the Idaho Territory and the Montana Territory followed the Bitterroot Range north of 46°30'N (as shown on the 1864 map). Popular legend says a drunken survey party followed the wrong mountain ridge and mistakenly moved the boundary west into the Bitterroot Range. Contrary to legend, the boundary is precisely where the United States Congress intended. The Organic Act of the Territory of Montana defines the boundary as extending from the modern intersection of Montana, Idaho, and Wyoming at: the forty-fourth degree and thirty minutes of north latitude; thence due west along said forty-fourth degree and thirty minutes of north latitude to a point formed by its intersection with the crest of the Rocky Mountains; thence following the crest of the Rocky Mountains northward till its intersection with the Bitter Root Mountains; thence northward along the crest of the Bitter Root Mountains to its intersection with the thirty-ninth degree of longitude west from Washington; thence along said thirty-ninth degree of longitude northward to the boundary line of the British possessions. The boundaries of Montana territory did not change during its existence. Montana was admitted to the Union as the state of Montana on November 8, 1889. Indian Wars Battle of the Little Big Horn The Battle of the Little Bighorn—also called Custer's Last Stand and the Battle of the Greasy Grass—was an armed engagement between a Lakota (Sioux)-Northern Cheyenne-Arapaho combined force and the 7th Cavalry of the United States Army. It occurred June 25–June 26, 1876, near the Little Bighorn River in eastern Montana Territory near present-day Hardin, Montana, on land that today is part of the Crow Indian Reservation. The Crow tribe sided with the U.S. army. George Armstrong Custer, with 257 troops attacked a much larger force of Native Americans, who were defending their civilian encampments, and in three hours the Custer battalion was completely annihilated. Only two men from the 7th Cavalry later claimed to have seen the battle: a young Crow whose name translated as Curley, and a trooper named Peter Thompson, who had fallen behind Custer's column, and most accounts of the last moments of Custer's forces are conjecture. Lakota accounts assert that Crazy Horse personally led