In the opening decades of the nineteenth century the entire American West was occupied by scattered bands of trappers. From the ranks of the “Fur Brigade” came Jedediah Strong Smith, a youthful fur trader, not yet thirty years old but experienced in his profession and well educated for his time. In the summer of 1826 he took his place at the head of a party of men organized to explore the unknown region lying between Great Salt Lake and the California coast. Smith’s leadership of this party gave him a first place in the history of the Sierra Nevada. His party left the Salt Lake rendezvous on August 22, 1826. A southwest course was followed across the deserts of Utah and Nevada, penetrating the Mojave country and the Cajon Pass. On November 27 they went into camp near Mission San Gabriel. Smith was thus the first American to make the transcontinental journey to California, the harbinger of a great overland human flood. The Spanish governor of California refused to permit the party to travel north as Smith had planned. Instead, he instructed that they should quit California by the route used in entering. Reinforced with food, clothing, and horses supplied by the friendly Mission San Gabriel, Smith returned to the neighborhood of the Cajon Pass. It was not his intention, however, to be easily deterred in his plan to explore California. He followed the Sierra Madre to the junction of the Coast Ranges and the Sierra Nevada and entered the San Joaquin Valley. He found the great interior valley inhabited by large numbers of Indians, who were in no way hostile or dangerous. There were “few beaver and elk, deer and antelope in abundance.” Reaching one of the streams flowing from the mountains, he determined to cross the Sierra Nevada and return to Great Salt Lake. Smith called this stream the Wimmelche after a tribe of Indians by that name who inhabited the region thereabouts. C. Hart Merriam has established the fact that Smith’s “Wimmelche” is the Kings River, and the time of his arrival there as February of 1827. Since the passes of the Sierra in this region are never open before the advent of summer, it is not surprising that his party failed in this attempted crossing of the range. Authorities have differed in their interpretation of Smith’s writing regarding his ultimate success in traversing the Sierra, but there is little doubt that he crossed north of the Yosemite region, perhaps as far north as the American River. Smith was, then, the first white man known to have crossed the Sierra Nevada. His pathfinding exploits did not take him into the limits of the present Yosemite National Park, but because his manuscript maps were made available to government officials who influenced later expeditions and because he was the first to explore the mountain region of which the Yosemite is an outstanding feature, his expedition provides the opening story in any account of Yosemite affairs.