Williamsport, Arizona is on the bank of one of the  principal rivers of the Southwestern United States and northern Mexico that is how long
Williamsport, Arizona: Williamsport, is a former mining town and present day ghost town, on the bank of the Colorado River in La Paz County, Arizona. Colorado River: The Colorado River is one of the principal rivers of the Southwestern United States and northern Mexico (the other being the Rio Grande).
i don't know