What did the jumanos use the rio grande for?

The Jumano people were a prominent indigenous tribe or several tribes, who inhabited a large area of western Texas, adjacent New Mexico, and northern Mexico, especially near the La Junta de los Rios region with its large settled Indian population. Spanish explorers first recorded encounters with the Jumano in 1581; later expeditions noted them in a broad area of the Southwest and the Great Plains. The last historic reference was in a 19th-century oral history, but their population had declined by the early 18th century.