Sault Ste. Marie is served by Interstate 75 from the south. This is the same highway that links Lower Michigan to the Upper Peninsula via the Mackinac Bridge. Sault Ste. Marie is at the northern terminus of I-75, about 50 miles north of the Mackinac Bridge. Two exits will get you into the Sault. 3 Mile Road is the first approaching from the south and takes you through most of the town via Business I-75. This route covers the main thoroughfare in town Ashmun Street and eventually gets you to Portage Avenue and the Soo Locks. The second and last in the USA exit off of I-75 is Easterday Avenue. This puts you virtually on the campus of Lake Superior State University to the east, or gets you more directly to Portage Ave. and the Locks to the west. The route is not quite as well-marked, however, and goes through some old and somewhat unattractive industrial areas. You bypass the downtown completely, which may not be so good, as you will miss lots of shopping, hotels and other amenities completely. But if you don't take this exit either, you will end up at the International Bridge toll and customs/immigration plaza for Canada. They will turn you around, without proper identification if you make this mistake. It's a hassle since traffic getting onto the bridge is often backed up in this area. Otherwise, crossing the border is reasonably easy. All you need is proper identification: a passport, passport card, Enhanced Driver's License, NEXUS, FAST, or SENTRI card, U.S. Merchant Mariner Documentation or U.S. Military Identification.
The "Sault Ste. Marie Michigan" airport is about 22 miles south of town, a former air force base along I-75. A shuttle bus & rental cars are available. The airport is served by Delta Air Lines, which offers daily flights to and from Detroit Metro Airport. There is also another small airport right in town that used to be the main airport years ago. After a long period of closure, it was re-opened for private planes a few years ago.
There is no rail service on the Michigan side, and buses from the Indian Trails bus line service Sault Ste. Marie Michigan regularly. The Mackinaw Shuttle Service also offers bus and limo service from its headquarters in Mackinaw City to Sault Ste Marie. Major carrier bus services were discontinued some time ago.
With all this in mind driving is about your only option. If you are headed for the Upper Peninsula anyway, it is definitely worth stopping in the Sault. It is also a great stopover if you are planning to continue on over to Canada, as the Michigan side tends to be less expensive for hotels, food, etc.
