Complex sentence: The Plains of San Augustin are on the floor of a basin formed along the southeast edge of the Colorado Plateau, and lie at the northern end of the Chihuahuan Desert, which is dominated by shrublands.
Split into simpler sentences: The Plains of San Augustin are on the floor of a basin formed along the southeast edge of the Colorado Plateau. The plains lie at the northern end of the Chihuahuan Desert, which is dominated by shrublands.