Complex sentence: The Tri-Cities are a group of three closely-tied cities (Richland, Kennewick, and Pasco) located at the confluence of the Yakima, Snake, and Columbia rivers in the semi-arid region of Southeastern Washington.
Split into simpler sentences: The Tri-Cities are a group of three closely tied cities in the southeastern part of the U.S. state of Washington (Richland, Kennewick, and Pasco). The cities are located at the confluence of the Yakima, Snake, and Columbia rivers in the semi-arid region of Southeastern Washington.