Correspondence between viceroy and Anza about overland expedition of later to open route to California from Sonora. Letters begin with Anza advising viceroy of recruiting of troops to substitute in presidio for men in expedition, his difficulties finding horses in area as Apaches had previously attacked presidio taking most horses. Anza purchases mules and leaves Tubac presidio January 1774 advising capitan Urrea and governor Crespo, obtaining as a guide capitan Yuma Tarabal, Anza goes to Altar presidio to buy horses. Anza worries about news of split between Yumas and crossing their lands. Anza lists 34 persons in expedition including frays Diaz and Garces. Anza encounters a Soyapa Indian who tells him of route and division of upper Colorado River; de Anza describes the physical stature of Yumas and mode of dress, also describes fertility of banks of Colorado and agricultural richness of area. Arrives at mission San Gabriel on April 1, 1774. Viceroy writes Anza with orders that if he encounters expedition coming from Loreto commanded by Moncada, they should together find best areas in San Francisco to construct two missions which will make it possible for more people to populate area. Anza returns to Tubac leaving Monterrey on April 22. Anza is transferred to presidio Terrenate and temporarily to Altar before he has sent an account of expedition to viceroy in Mexico City. In subsequent letters Anza relates meeting Junipero Serra sixty leagues before Monterrey in his return, also relates taking six soldiers from Monterrey with him to show them route to Rio Colorado and sending them back before leaving for Tubac, in subsequent letters Anza waits for many months before being ordered to travel to Mexico but cannot take trip before he pays amounts loaned from merchants to pay for expedition for which Anza request monies from viceroy. Viceroy writes de Anza consulting him based on personal explorations if route to New Mexico from Sonora and from New Mexico to Monterrey could be possible, de Anza relates based on experience and accounts by a Pima enslaved by people from New Mexico who escapes and crosses land in seven days. Anza calculates distance from Sonora to New Mexico 180 leagues and from Monterrey to New Mexico 368 leagues, advising if exploration should be taken it should start in September, earlier is too dry and later danger of snow is maximized. de Anza advises viceroy of danger crossing Apache lands and advises a person taking this expedition should know and understand territory and its people, de Anza offers himself as Head of this expedition to viceroy as best suited for the undertaking. Fray Garces comunicates with de Anza about his explorations in upper Colorado indicating encounter with Cocomaricopas and other people that dress, speak, and are similar physically to Apaches, fray Garces believes that a route thru Colorado River is possible to New Mexico based on accounts given him by new Indians he encountered. (A. Dell'acqua December 1987)