An agreement was reached on July 7, 1883, for the government to purchase the entire Columbia Reservation from the Indians. Those families formerly assigned to the reservation were to be given the choice of moving to the Colville Reservation or taking allotments of one section (1 sq mi or 2.6 km²) of land each. By act of Congress on July 4, 1884, the entire reservation was restored to the public domain. On May 1, 1886, it was formally reopened for white settlement. The influx of settlers was so great that Okanogan County (roughly the same area as the Columbia Reservation) was split from Stevens County two years later.