Oklahoma's '89er Day Celebration, is an annual April event commemorating Oklahoma's first land run, held on April 22, 1889, to open the Unassigned Lands of central Oklahoma to non-Indian settlement. The celebration occurs in various cities contained within the historic boundaries of the Unassigned Lands, a 1.8-million-acre geographic area that was bordered by the Cherokee Outlet on the north, the Chickasaw Nation to the south, the Cheyenne and Arapaho Reservation to the west, and the Shawnee, Sac and Fox, Iowa, Pawnee and Potawatomi reservations on the east.