Riverside County encompasses more than two million people and most of the width of California, from Los Angeles’s eastern suburbs to the Arizona state line at the Colorado River. Historian Steve Loch captures the vanished past of this vast swath of deserts and mountains—the eras of Spanish and then Mexican rule and the exploits of the earliest settlers of the American period. Juan Bautista de Anza, Louis Robidoux and many other namesake figures of today’s geography are described in this unabridged excerpt of the author’s comprehensive and masterly history Along the Old Roads.