Answer:
Navajo
Step-by-step explanation:
The tribe that saw its population grow significantly after going to a reservation and returning to ancestral ways of herding horse, sheep, and goats is known as the NAVAJO (or NAVAHO) tribe.
This is evident in the fact that the Navajo people are considered to be the biggest federally recognized tribe in the United States with over 600,000 enrolled members as of 2020.
The Navajo Nation covered about 70,000 kilometer square in territory.