Since 1974, Markley Marine has been a summer destination for boaters on the Clinton River in Harrison Township. With 500 slips, we're the largest marina on the Clinton River, and you'll enjoy all the advantages of our location. By boat, you're only minutes from Lake St. Clair. By car, you're only minutes from I-94. Unlike some marinas, there's no public restaurant, no public gas dock, and no sales showroom to compromise your privacy and security. It's like being in your own private club. On the Clinton River, you'll find gas docks and restaurants, and easy access to the summertime fun of Mt. Clemens.