In 1775–1776, Francisco Garcés, O.F.M., undertook a remarkable three-thousand-kilometer journey through modern Arizona and the Californias. As a participant in a side-branch of Juan Bautista de Anza’s colonizing expedition to San Francisco, Garcés recorded a diary that provides a fascinating glimpse of Native peoples, several who had minimal or no prior contact with the Spanish empire. Garcés described customs, detailed alliances and enmities, and offered recommendations, both missionary and military. When he reached Hopi from the west (the first European to do so), Garcés completed a route between Monterey and Santa Fe, in effect completing a road across North America a generation before Lewis and Clark. The Hopi leaders, who clearly understood the implications, expelled him, declaring their independence on July 4, 1776.  Garcés’s diary remains vital for the Indigenous history of western North America. Yet the standard translation is flawed, not least owing to the state of ethnographic knowledge when it was made (1900), resulting in more than a century of reiterated misinterpretations of Indigenous history by anthropologists and historians. Peter M. Whiteley identifies the ur-version of Garcés's diary—a previously unknown copy written up by Pedro Font—and offers a new translation focusing on ethnographic significance in geographic context. Presenting also the Spanish text, Whiteley engages directly with Garcés’s account and provides readers with new interpretation and context. Garcés was a genuine ethnographer and his accounts of Hopi, River Yumans, Takic, Yokuts, Numic, and Pai peoples, contain unparalleled and foundational insights.