[1] Esmerelda was built in San Francisco at the 3rd Street shipyard of Patrick Henry Tiernan at Steamboat Point in 1862 for Captain Washington Pitts.
Of a type commonly used on the San Francisco Bay and Sacramento River and its tributaries, the barge was 128 x 28 feet capable of carrying 100 tons of freight.
In early May Trueworthy took the Esmerelda up river for the first time with the Black Crook in tow making it to Fort Yuma in three days, eight hours.
Johnson associate William Harrison Hardy had succeeded in getting there first, leaving January 2, poling and sailing (when the wind was favorable) a 50 by 8 foot flat boat "Arizona" 90 miles from Hardyville to Callville in 12 days.
[1]: 47, 48 In the summer of 1865, Esmerelda was consolidated with the other rival boat, into the Pacific and Colorado Steam Navigation Company, also headed by Thomas E. Trueworthy, with backing from San Francisco financiers.