Nearly every visitor to Sault Ste. Marie makes a pilgrimage to the locks, right in the heart of downtown at the end of Ashmun Street (Business I-75). The city has smartly dressed up this area beautifully, with lovely Brady Park. Blue freighter signs mark the Locks Park Walkway, which wanders along Water Street and is dotted with interpretive plaques that share the city’s history.

In the heart of the rather formal park, the U.S. Army Corps of Engineers manages the locks and a visitors center (Portage Ave., 906/932-1472, www.soolocksvisitorscenter.com, 9 a.m.–9 p.m. daily, free), next to a raised viewing platform that lets you peer down on the action. Start at the visitors center to make sense of what’s happening. Here, a moving model shows how the locks raise and lower ships by opening and closing the gates of a lock chamber and allowing water to rush in or rush out. No pumps are required; the water simply seeks its own level.

Other displays explain the construction of the locks. A knowledgeable staff with a P.A. system, along with video cameras upriver, notify you about approaching vessels. In summer months, you can usually count on a ship coming through every hour or so. The visitors center will have the day’s shipping schedule, but be aware that times can change depending on weather conditions and other factors.

It’s easy to while away an hour or two watching the ships as they slither into the locks with seemingly just inches to spare. Summer evenings are especially pleasant, when you’ll likely have the platform to yourself to watch the illuminated ships. If you’re lucky, you might see a “saltie,” an oceangoing vessel that’s likely hauling grain to foreign ports. Overall, the three most plentiful Great Lakes shipments are iron ore (for steelmaking), limestone (a purifying agent for steelmaking, also used in construction and papermaking), and coal (for power plants).

The locks and viewing platform are open throughout the Great Lakes shipping season, which runs March 25–January 15. Those are the official dates when the locks cease operation for maintenance; ice build-up on Superior sometimes affects the length of the shipping season, too. The visitors center is open mid-May–mid-November.