Question: The Crow Scouts were involved in the only armed conflict between the United States and the Crow tribe of which US state?

Context paragraphs:
Crow War: The Crow War, also known as the Crow Rebellion, or the Crow Uprising, was the only armed conflict between the United States and the Crow tribe of Montana, and the last Indian War fought in the state.  In September 1887 the young medicine man Wraps-Up-His-Tail, or Sword Bearer, led a small group of warriors in a raid against a group of Blackfoot which had captured horses from the Crow reservation.  Following the raid, Sword Bearer led his group back to the Crow Agency to inform the Indian agent of his victory, but, an incident arose which ended with the young leader taking his followers into the mountains.  In response, the United States Army launched a successful campaign to bring the Crow back to the reservation.

Crow religion: Crow religion is the indigenous religion of the Crow tribe, Native Americans of the Great Plains area of the United States.

Crow scouts: Enlisted Crow Scouts were first used by the United States Army in 1876 during the Great Sioux War.  Because the Crow tribe was peaceful with the Americans and in particular, because parts of the old Crow country was flooded with hostile Lakotas, Northern Cheyennes and Arapahoes (Northern Arapaho), the army was able to enlist Crow warriors to help track hostile Native Americans.  Already in 1873, the Crows had called for U.S. military actions against the Indian invaders in the Crow reservation.  They were just waiting to offer their expertise.  A small group of Crow scouts witnessed General George A. Custer's defeat at the Battle of the Little Bighorn in the Crow reservation.  Many Crows served against the Nez Percés in 1877, and again in the Bannock War the next year.  Crow scouts rode along with Assiniboines, Bannocks and Cheyennes during Colonel Nelson A. Miles search for Sitting Bull north of the Missouri in 1879.  Some former scouts fought in the Crow War of 1887.

Dakota War of 1862: The Dakota War of 1862, also known as the Sioux Uprising, Dakota Uprising, the Sioux Outbreak of 1862, the Dakota Conflict, the U.S.–Dakota War of 1862 or Little Crow's War, was an armed conflict between the United States and several bands of Dakota (also known as the eastern 'Sioux').  It began on August 17, 1862, along the Minnesota River in southwest Minnesota.  The war saw extensive attacks on hundreds of settlers and immigrants, and caused many to flee.  Intense desire for immediate revenge ended with the mass execution of 38 Dakota men on December 26, 1862, in Mankato, Minnesota.

Crow Agency, Montana: Crow Agency is a census-designated place (CDP) in Big Horn County, Montana, United States and is near the actual location for the Little Bighorn National Monument and re-enactment produced by the Real Bird family known as Battle of the Little Bighorn Reenactment.  The population was 1,616 at the 2010 census.  It is the governmental headquarters of the Crow Native Americans.  It is also the location of the "agency offices" where the federal Superintendent of the Crow Indian Reservation and his staff (part of the Bureau of Indian Affairs, United States Department of the Interior) interacts with the Crow Tribe, pursuant to federal treaties and statutes.

Ex parte Crow Dog: Ex parte Crow Dog, 109 U.S. 556 (1883) , is a decision of the Supreme Court of the United States that followed the death of one member of a Native American tribe at the hands of another on reservation land.  Crow Dog was a member of the Brulé band of the Lakota Sioux.  On August 5, 1881 he shot and killed Spotted Tail, a Lakota chief; there are different accounts of the background to the killing.  The tribal council dealt with the incident according to Sioux tradition, and Crow Dog paid restitution to the dead man's family.  However, the U.S. authorities then prosecuted Crow Dog for murder in a federal court.  He was found guilty and sentenced to hang.  The Supreme Court held that unless authorized by Congress, federal courts had no jurisdiction to try cases where the offense had already been tried by the tribal council.  Crow Dog was therefore released.  This case was the first time in history that an Indian was held on trial for the murder of another Indian.  The case led to the Major Crimes Act in 1885, which placed some major crimes (initially seven, now 15) under federal jurisdiction if committed by an Indian against another Indian on a reservation or tribal land.  This case was the beginning of the plenary power legal doctrine that has been used in Indian case law to limit tribal sovereignty.

Red Cloud's War: Red Cloud's War (also referred to as the Bozeman War or the Powder River War) was an armed conflict between the Lakota, Northern Cheyenne, and Northern Arapaho on one side and the United States in Wyoming and Montana territories from 1866 to 1868.  The war was fought over control of the western Powder River Country in present north-central Wyoming.  This grassland, rich in buffalo, was traditionally Crow Indian land, but the Lakota had recently taken control.  The Crow tribe held the treaty right to the disputed area, according to the major agreement reached at Fort Laramie in 1851.  All involved in "Red Cloud's War" were parties in that treaty.

Crow Indian Reservation: The Crow Indian Reservation (est. 1868) is the homeland of the Crow Tribe of Indians of the State of Montana in the United States.  The reservation is located in parts of Big Horn, Yellowstone, and Treasure counties in southern Montana.  It has a land area of 3,593.56 sq mi (9,307.27 km²) and a total area of 3,606.54 sq mi (9,340.89 km²), making it either the fifth or sixth largest reservation in the country.  (Rankings are switched with the Standing Rock Indian Reservation depending on whether water areas are counted.)  Reservation headquarters are in Crow Agency.

Battle of Lower Sioux Agency: The Attack at the Lower Sioux Agency was the initial action of the Dakota War of 1862 in August.  After the initial conflict at Acton Township, Minnesota on August 17, in which five white settlers were killed, tensions were running high within the Lower Sioux tribe.  The Sioux or Dakota feared that the murders would bring about a reprisal from United States forces.  Chiefs Shakopee and Red Middle Voice convened a council at Little Crow's village near the Lower Sioux Agency to discuss the situation.  Although Little Crow was hesitant to go to war, because of the strength of United States troops, Little Crow was threatened and berated, eventually convinced to lead a war to drive the settlers from the Minnesota River valley.

Iraq War: The Iraq War, also known as the Second Gulf War, was a protracted armed conflict that began in 2003 with the invasion of Iraq by a United States-led coalition that overthrew the government of Saddam Hussein.  The conflict continued for much of the next decade as an insurgency emerged to oppose the occupying forces and the post-invasion Iraqi government.  An estimated 151,000 to 600,000 or more Iraqis were killed in the first 3–4 years of conflict.  The U.S. became re-involved in 2014 at the head of a new coalition; the insurgency and many dimensions of the civil armed conflict continue.  The invasion occurred under the pretext of a declared war against international terrorism and its sponsors under the administration of US President George W. Bush following the September 11 terror attacks.

Supporting paragraphs: Crow scouts Crow War
Answer: Montana