The Coeur D’Alene Tribe (Tribe) resided in the area now known as Idaho (defendant) before it was a state. The United States (plaintiff) attempted to negotiate the relinquishment of most of the Tribe’s land in exchange for a reservation. The original offer by the United States was rejected when it did not give the Tribe access to the waterways the Tribe’s members relied upon for fishing and sustenance, including the St. Joe River and Lake Coeur D’Alene. After additional negotiation, the United States redrew the reservation boundary lines to ensure parts of these waterways were included in the Tribe’s reservation land, subject to final approval from the Tribe. The Tribe agreed to the newly drawn reservation, but the reservation was not ratified by Congress. While the reservation was awaiting ratification, Congress passed an act admitting Idaho to statehood. Shortly after, Congress ratified the reservation agreement with the Tribe. The United States, acting on behalf of the Tribe, sued to quiet title to the submerged lands underneath the parts of the St. Joe River and Lake Coeur D’Alene located on the reservation. The United States and the Tribe argued that the lands belonged to the Tribe, while Idaho argued the lands were conveyed to it upon it becoming a state. The district court found in favor of the United States, as did the United States Court of Appeals for the Ninth Circuit. The United States Supreme Court granted certiorari.