With the discovery of the Gila Placers by Jacob Snively came the first Arizona gold rush in 1858-1859, which created the ephemeral Gila City just east of Fort Yuma on the Gila River. Early in 1859, placer gold was found eighteen miles above Fort Yuma at the Pot Holes on the west bank of the Colorado River in California. In August 1859 Johnson retired the General Jesup and replaced it with the 140 foot Stern-wheeler Cocopah. Its shallow 19 inch draft and stern-wheel was better suited to transit the upper Colorado route, and was the model for all the steamboats on the river thereafter. In 1860, gold was found in placers at La Laguna.: In April 1861, as the American Civil War began, word got out that silver and gold lodes had been discovered by John Moss and others in El Dorado Canyon, sixty five miles above Fort Mohave near what was then considered the high water limit of navigation. George A. Johnson came up river and made a deal to supply the mines with his steamboats at $100 a ton, a lower price than the $240 a ton charged for overland freight across the Mohave Desert from Los Angeles.