The First Scientific Mapping of The Colorado River
Fine map of the Southwestern United States, showing the course of the Colorado River from its source in the mountains of western Colorado to the mouth of the Colorado in the Sea of Cortez.
The first map shows the topography and geology of the lower Colorado River in four panels, beginning in Black Canyon at Fortification Rock and ending in the Sea of Cortez (Gulf of California). The map locates and names Pt. Invincible, Ogden's Landing, Fort Yuma, Lighthouse Rock, The Needles, the location of Beale's Crossing, Bullshead (today's Bullhead City), Painted Canyon, Fortification Rock, and much more. Numerous rapids are noted including Roaring Rapid 3 large rocks & one sunken rock below, and Violent Rapid with rocks on both sides.
The map is from a series of four and represents one of the most important exploring efforts of the American Southwest.
Carl Wheat devotes several pages to these maps.
The main object of the Ives Expedition was to assess the navigability of the Colorado for possible use as a transportation corridor into California, Utah, and New Mexico, which then included Arizona. Lieutenant Joseph Christmas Ives, who had been with Joseph Whipple's railroad survey a few years earlier, was selected to command the expedition.
Ives hired several experienced men to help him, including Baron F.W. von Egloffstein, a topographer and artist. He had a shallow-draught steamboat constructed and shipped to the mouth of the Colorado River in pieces. The boat, named the Explorer, was assembled in the lower delta and then used to explore the river most of the way to Las Vegas Wash.
When the river exploration was complete, Ives sent the boat downriver and converted to pack mules to travel eastward cross-country to the settlements in New Mexico. Along the way, they became the first European Americans to visit the Colorado River at the bottom of the Grand Canyon. They also were the first to follow the Havasupai Trail to the bottom of the canyon.
Another first that came out of this expedition was a new style of map drawing invented by Baron von Egloffstein for the official expedition maps. Instead of tediously-drawn hachures to show terrain relief features, Egloffstein used a shaded relief style, which is still preferred for modern maps. He also invented and patented a usable halftone printing process in order to successfully print his new continuous tone maps.