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- -' 00 - ,- ~. A Dangerous Obstacle Many rivers have served as arteries for exploring the wilderncss. But the Col- orado blocked rather than helped explora- tion. Travelers f()Und it a dangerous obstaclc and detoured hundreds of miles to avoid its hazards and bypass its canyons. The venturesome few who at- tempted to trace its course were punished by extraordinary hardship, even death, for their lack of caution. The river could be crossed at only a few favorable points. When gold was discovered in California in 1848, hordes of adventurers tlocked westward. Many followed a southern route that took them across the Colorado near its junction with the Gila River. According to one histo- rian, IO,DOO people crossed the river there in 1849-50. But the Grand Canyon area, roughly 500 miles to the north, re- mained unconquered. The treaty ending the Mexican War in 1848, and the Gadsden Purchase which was ratified in 1854, added the territories of New Mexico, Arizona, and Califomia to the United Statcs. After thcse terri- torics were acquired, the unknown stretches of the lower Colorado River needed to be explored. In 1857 the War Department dispatched Lt. LC. Ives to proceed up the Colorado by boat as far as possible from the Gulf of Califomia. Ivcs started his trip early in 1858, and succeeded in bringing his steam boat, 77w Explorer, about 400 miles upstream before wrecking it on a submerged rock at the lower end of Black Canyon. He then proceeded by skiff through the canyon, past the point where Hoover Dam now stands, until he reached Las Vegas Wash, approximately 5 miles upstream. Viewing the Colorado as a potential avenue of transportation, Ives submitted a report which said: ''/ wOlt/,1 again state my belief that the Colorado would be found an economical avenue for the trampOJ1ution of supplies to fIlilitmyoutposts in New Me:rico and 10 Utah. . . . The first organization of trans- ponation establishments, to connect the upper part of the river with the interior of the Territories mentioned, would be at- tended with expense and trouble; but I am convinced that it would ultimately be pro- ductive of a great saving in both. However, of the Grand Canyon area, which he also visited, Ives had this to say: 'The region last explored is, of course, altogether valueless. It can be approached only from the south, and after entering it there is nothing to do but to leave, Ours ww' the first, and will doubtless be the last, party of whites to visit this profitless locality. It seems intended by Nature that the Colorado River, along the greater portion of its lonely and majestic way, shall be forever unvisited and undisturbed. ~ Twelve years later. Maj. John Wesley Powell successfully led a river expedition through the canyons of the Colorado. PoweIrs patty traveled downstream from the Green River in Wyoming to the mouth of the Virgin River in Nevada. Powell and his companions, covering 1,000 miles of uncharted rapids and treacherous canyons, were the first to gaze from a boat up at the sheer walls of Grand Canyon and live to tell the story. Even before LL lves and Maj. Powell explored the river, others had seen the possibilities of using its water to irrigate the rich and fertile lands in southem California's Imperial Valley. The idea is reflected in several writings of the 1850.s, but it was not until some 40 years later that actual development began. The privately owned Califomia De- velopment Company began constructing irrigation canals in 1896, and the first Colorado River water reached Imperial Valley fields in 190 I. The water flowed through a canal that looped through Mex- ico for about 60 miles, following the old Alamo River, one of the Colorado's overflow channels, much of the way. But this system could not assure a stable water supply for the valley's irrigated lands. Flood. . .and Drought Like other western streams, the Colorado River usually ran high in the late spring and early summer. Fed by rapidly melt- ing snows, the river frequently swelled to a torrent that swept over its banks and in- undated land for miles around. Following these high water periods, the flow was often too low for diversion. These ir- regularities presented many difficulties for irrigators along the lower river in the early 1900's. When flooding, the river carried im- mense quantities of sediment, which clogged diversion head works and irriga- tion canals, creating serious water de- livery and maintenance problems. And, without irrigation water, growing crops rapidly withered and died. The heavy flooding also led to high costs for building head works and levees to handle the flows-or repair them after the floods subsided. Low flows also caused difficulties. Special diversion works were needed for these periods, and, because low flows were a recurring problem, the amount of land that could be successfully irrigated was limited. Also, water diverted by users farther up the river caused still worse shortages downstream. A particularly devastating flood hit the lower river in 1905, when a combination of sediment difficulties, unseasonal flash floods, and regular spring and early sum- mer JUnoff caused the Colorado to change its course and flow uncontrolled into the Imperial Valley for more than a year. The Imperial Valley is like a deep saucer. Its lowest point, the Salton Sink, was about 280 feet below sea level in 1900. Its southeastern rim, along which the Colorado River flows for a short distance, was roughly 100 feet above sea level near the United States-Mexico boun- dary. The descent from the valley's rim to the Salton Sink, once established on a uniform grade, was much steeper than the descent to the Gulf of California, the river's natural outlet.