Complex sentence: Nomadic Southern Athabaskan speaking peoples, such as the Apache and Navajo, succeeded the Pueblo people in this region by the 15th century; in the process, they acquired Chacoan customs and agricultural skills.
Split into simpler sentences: Nomadic Southern Athabaskan-speaking peoples, such as the Apache and Navajo, succeeded the Pueblo people in this region by the 15th century. In the process, they acquired Chacoan customs and agricultural skills.