Pedro (Pierre) Vial, a remarkable pathfinder in the Spanish Southwest, was born in Lyons, France, most likely in the middle decades of the eighteenth century. In remarks made about himself, Vial hinted that he had become familiar with lands along the Missouri River prior to the American Revolution; he first attracted the attention of Spanish authorities with his appearance in Natchitoches and New Orleans in 1779. Vial came to San Antonio in the fall of 1784 after living for a time among the Taovaya Indians. He was immediately selected by Governor Domingo Cabello y Robles to gather information about the eastern Comanches, who were associates of the Taovayas. In the company of Francisco Xavier Chaves, Vial spent the summer months of 1785 within Comanchería. In the following year, Cabello charged Vial with finding the most direct route between San Antonio and Santa Fe. Typically a loner, the French pathfinder set out on October 4 with only one companion, Cristóbal de los Santos, a native of Bexar. His responsibilities included keeping a diary in which he was to record distances traveled, Indians encountered, and the size of native encampments. Vial soon fell ill and possibly became disoriented. In any event, he traveled northward by way of Tawakoni villages near present Waco and then continued on to the Red River, where he lived for a time with the Taovayas.
From the Taovaya villages, Vial followed the Red and Canadian rivers westward and reached Santa Fe on May 26, 1787. In traveling this circuitous route, he had covered approximately 1,000 miles. Slightly more than a year after his arrival in Santa Fe, Vial set out for Natchitoches by way of the Texas Panhandle and the Red River. From Natchitoches he then trekked to San Antonio, followed by a second journey to Santa Fe-covering in all an estimated 2,377 miles in fourteen months. In successive summers (1792–93), Vial traveled over what would become the Santa Fe Trail, making a round trip-estimated at 2,279 miles-between Santa Fe and St. Louis. His feats included safe passage through lands occupied by such diverse Indian groups as Apaches, Comanches, Kansas, Osages, Arapahos, Pawnees, and Sioux. Aside from his major explorations, which linked Santa Fe to San Antonio, Natchitoches, and St. Louis, Vial regularly served the governor of New Mexico as interpreter and agent in Indian country. Five years after his trip to St. Louis, Vial left the Spanish to live among the Comanches, but in 1799 he resided at Portages des Sioux, to the north of St. Louis. By 1803 he was back in Santa Fe, where he died in 1814. His will indicated that he had never married and did not leave children.