transferred their cargo directly to the river steamers.40 These in turn transported both freight and passengers upstream to the post. This operation required from several days to as many weeks, depending on the stage of the river and the good fortune of the pilot in getting through. Meanwhile the ocean-going vessels were required to ride at anchor until the entire cargo was discharged.41
Up to 1856, trade was confined entirely to Fort Yuma, but when miners began to open claims along the river Johnson became interested in the possibility of navigating the river above this point. In 1856, after obtaining the support of the Callfornia legislature, he went to Washington, where he succeeded in getting an appropriation of seventy-five thousand dollars to determine the navigability of the Colorado above Yuma. The money was not spent, and when a change of administration occurred. Lieutenant Joseph C. Ives was appointed to carry on this investigation. Ives wrote to Johnson asking for particulars about the river and inquiring about the probable cost of transporting a party to the head of navigation. Johnson replied that he believed $3,500 would cover the cost and offered the use of one of his boats. Ives, however, determined to act independently.42 On November 1, 1857, he left San Francisco for the mouth of the Colorado River on the 120- ton Monterey. His party included technicians for the study of the surrounding country and was prepared to make extensive observations and maps of the area.
On board the Monterey were parts for the fourth boat to operate on the river, the small iron-hull steamer Explorer. She was built in Philadelphia and was so constructed that after her trial runs on the Delaware River she could be dismantled and shipped to San Francisco by way of Panama. Assembly took place at the mouth of the river during December, and just a month from the date of her arrival she was launched by moonlight at high tide on the thirtieth. In spite of the fact that she had been an expensive and unnecessary investment and that she was less than half the size of Johnson's Colorado^ Ives proudly surveyed her and wrote: "This morning the 'Explorerunderwent a critical inspection. She is fifty-four feet long from the extremity of the bow to the outer rim of the stern wheel. Amidships, the hull is left open, like a skiff, the boiler occupying a third of the vacant space. At the bow is a little deck, upon which stands the armament— a four-pound howitzer."43
Captain D. C. Robinson was secured from the Johnson Company to pilot the Explorer, since he had had considerable experience on the river. The expedition got under way on December 31, 1857. After proceeding some distance, Ives left the boat and proceeded overland to the fort, where other members of his expedition were awaiting him. Here he experienced a great disappointment, one which he scarcely mentions in his voluminous report.
Johnson, who had been instrumental in getting the government appro
