The park is on the shore of Lake Superior, and most of the beach areas are rocky. However, a stretch of land on the edge of the park near the Keweenaw Waterway is sandy and good for swimming. This area is known as the Breakwaters, known to some locals as just the "Breakers." There are also good swimming areas adjacent to the campground.
McLain is a good jumping off point for exploring the Keweenaw Peninsula as it is between the Historic towns of Calumet and Houghton/Hancock. It is a popular destination for (non-motorized) bikers -- mountain bikers and road bikers as it has many trails through and near the park, and the park is situated approximately 10 miles from both cities which have strong biking traditions and many trails.
McLain State Park is also home to a campground, complete with showers and bathrooms. This campground is very popular in the summertime with locals and tourists alike. The park is also known for its beautiful sunsets over Lake Superior. It has about 80 campsites all of which are on or near the water's edge and a handful of small and rustic cabins, most of which sleep 4. They have one cabin that sleeps 8 and has a small primitive kitchen area. There are playgrounds scattered throughout.
Pedestrian access to the park is always free, and there is a free parking area outside the gates for those wishing to walk in. There is a nominal fee to enter the park with a car or use the campground.
During the first week of the fall semester, Michigan Technological University holds "K-Day" (or "Keweenaw Day") at the park. The university cancels afternoon classes so that students and faculty can enjoy a day of fun, sun, music, games, and food.
The spelling of the park's name is inconsistent on roadsigns and in local publications, varying between "McLain", "MacLain", and "McClain." The proper name is indeed "McLain".