Complex sentence: Lake Michigan and Lake Huron are sometimes considered to be a single lake, Lake Michigan-Huron because they behave hydraulically as a single body of water due to their substantial connection at the Straits of Mackinac.
Split into simpler sentences: Lake Michigan and Lake Huron are sometimes considered to be a single lake, Lake Michigan-Huron. They behave hydraulically as a single body of water connected at the Straits of Mackinac.