On, December 17th, two steamers appeared from the fort, in command, respectively, of Johnson and Wilcox, to transport the army supplies to their destination.

Robinson, after whom the landing was called because he had a cabin there, was with the steamboats, and, as he knew the river, especially as far as Yuma, Ives engaged him for pilot.
By the end of the month, the Explorer, as the Ives boat was named, was ready for the expected high tide.

She was fifty-four feet long over all, not quite half the length of Johnson's Colorado.

Amidships she was open, but the bow was decked, and at the stern was a cabin, seven by eight feet, the top of which formed an outlook.

For armament, she was supplied on the bow with a four-pound howitzer, though this weapon was not likely to be of much service.