Cathcart Campground. . . This unique campground, situated on the banks of the St. Clair River, has an island accessible by a walking bridge for you to enjoy a family picnic by the water as you watch the river traffic (ships, sailboats, motorboats, etc) cruise by. Walk or bike the St. Clair River Trail to the quaint village of Sombra (just a short distance away) with its specialty shopping and car ferry service to Marine City, Michigan. Please call ahead to book or regarding any specific requirements.