The Colville Confederated Tribes Sprawling across more than 1, 000, 000 acres (AID, 38) or 2, 300 square miles of northeast Washington State is the Colville Reservation - that is larger than the state of Rhode Island. The reservation is named after Fort Colville, a British outpost established in the 1820s. ( Who are the Colville Indians, Colville Tribal Museum, Grand Coulee, WA). It was established ...