Complex sentence: Chapter II Today, this valley contains the Minnesota River, joined by the Upper Mississippi River at Mendota, Minnesota, and the northern part of the former lakebed is the valley of the Red River of the North, which flows northward to Lake Winnipeg.
Split into simpler sentences: Chapter II Today, this valley contains the Minnesota River, joined by the Upper Mississippi River at Mendota, Minnesota. The northern part of the former lakebed is the valley of the Red River of the North, which flows northward to Lake Winnipeg.