Editing Yuma, Arizona (section)

===Early development===

From 1854, Colorado City was the major steamboat stop for traffic up and down the Colorado River.  After the 1862 flood, it became part of Arizona City.  The steamboats transported passengers and equipment for the various mines and military outposts along the Colorado; Colorado City was the terminus of wagon traffic up the Gila River into New Mexico Territory.  They offloaded the cargo from ships at the mouth of the Colorado River at [[Robinson's Landing]] and from 1864 at [[Port Isabel, Sonora|Port Isabel]].  From 1864, the [[Yuma Quartermaster Depot]], today a state historic park, supplied all forts in present-day Arizona, as well as large parts of Colorado and New Mexico. After Arizona became a separate territory, Yuma became the county seat for Yuma County in 1871, replacing [[La Paz, Arizona|La Paz]], the first seat.

The [[Southern Pacific Railroad]] bridged the river in 1877, and acquired [[George Alonzo Johnson]]'s [[Colorado Steam Navigation Company]], the only steamboat company on the river.  Yuma became the new base of navigation on the river, ending the need for Port Isabel, which was abandoned in 1879.  The warehouses and shipyard there were moved to Yuma.