From Pueblo Kachinas and Impersonators, by Ava Coleman:

“Knitting was a skill that could have been introduced to Southwestern Pueblo Americans as early as the sixteenth century by Spanish soldiers or priests who came into the Four Corners area as explorers. It could have been introduced as much as a century later as the area was settled. It is known, however, that by the mid-1800s knitting was a well-established craft. It was even taught as a subject to students of both genders at the Indian Schools, during a particularly sad time when children were forced to leave the Pueblos and their families.”

This pattern includes instructions for a traditional and a modern version of knitting leggings.