46 C.F.R. § 45.175
Applicable routes
This subpart applies to the following routes, including intermediate ports, on Lake Michigan, between Calumet Harbor, IL, and—
(a) Milwaukee, WI (the “Milwaukee route”);
(b) Burns Harbor, IN (the “Burns Harbor route”);
(c) St. Joseph, MI (the “St. Joseph route”); and
(d) Muskegon, MI (the “Muskegon route”).