The route of the gold-seeking Forty-niners from Salt Lake to Los Angeles approximates the modern highway U.S. 91. This trail has had a long and interesting history. Its southern half was identical with the western end of the Old Spanish Trail that extended from Santa Fé to Los Angeles;1 its northern half was utilized primarily by the Mormons.
Although the Forty-niners, whose diaries are reproduced in this volume, were the first to take wagon caravans over this route, the Old Spanish Trail portion had long been used in the pack horse commerce between New Mexico and California.
The pioneer explorations of this western region had been undertaken in 1776 as a part of the general plan to open a pathway between New Mexico and California, with a view toward re-enforcing the new, struggling California missions by sending aid from the old and well-established settlements of New Mexico.
Father Garcés, famous explorer of the desert trace from the Gila River to southern California, was the first white man to discover and follow the course of the Mojave River, that lifesaving stream which made possible the Old Spanish Trail and the Salt Lake-to- Los Angeles route across the desert.2____________________