When Bryon Schroeder moved to Alpine, Texas, in 2016, he was amazed at how few rules there were. In Texas—unlike in Wyoming, where he grew up, and in Montana, where he got a Ph.D. in archeology—if you have permission to dig on someone’s land “you don’t really have to do any permits or anything,” he told me. “Here, you can’t tell landowners not to do stuff. This is Texas, goddammit!”

Schroeder is thirty-eight, with a tangle of curly hair and a taste for Hawaiian shirts. He came to Alpine to work for the Center for Big Bend Studies, which he now runs. The Center, a research institute focussed on archeology and history, is affiliated with Sul Ross State University, an agriculture-focussed school that calls itself “the frontier university of Texas.” At Sul Ross, Schroeder is the only full-time faculty member in the anthropology department, and he sometimes finds himself teaching introductory courses to all of four people. But living in Alpine gives easy access to craggy limestone country, where the history of human occupation dates back at least ten thousand years.

More than ninety-five per cent of Texas is privately owned, so nearly all digs require coöperation from a landowner. Schroeder met Jeff Fort, who owned a sixty-thousand-acre ranch that spanned a stretch of dramatic canyons in the Big Bend region of West Texas. Fort was fascinated by deep time. Exploring his property, he had found petroglyphs carved on boulders, shards of pottery, and more than a hundred rock shelters. “I haven’t found a dinosaur yet, but I’d like to,” Fort, a rangy, tireless man in his eighties, told me. With Fort’s blessing, Schroeder toured the ranch’s suspension-ruining dirt roads in a pickup truck, and he accompanied Fort on ten-mile hikes through washes and along old game trails. In a number of places, rainwater had worn away Cretaceous limestone, resulting in rock shelters and caves.

Fort suggested that Schroeder look at one cave in particular. “He didn’t tell me how to get there, exactly,” Schroeder recalled. “He just told me, ‘You’ll see it.’ ” The road was too rugged for the truck, so Schroeder took an A.T.V. Eventually, he came upon a cave with two triangular openings sitting atop a talus slope sprinkled with burned rock, the remnants of ancient agave-baking pits. The soil around the cave was black from cooking fires and organic materials. “You could just tell how long people had lived at this site,” Schroeder said.

Recent excavations suggest that the area was the easternmost outpost of Southwestern Puebloan culture, and was later inhabited by a number of semi-nomadic groups, including the Chisos and the Jumano. By the end of the eighteenth century, many of these groups had been wiped out or assimilated by the Apache, some of whom had migrated south from the Great Plains. A century later, Texas’s Indigenous populations were subjected to a series of brutal assaults: the systematic slaughter of buffalo, incursions by Anglo settlers, and military campaigns with the goal of extermination. By the dawn of the twentieth century, many Native groups had moved to Oklahoma, retreated to Mexico, or been killed.