Russell Island is a small private island in the St. Clair River in the U.S. state of Michigan between Algonac and Walpole Island, Ontario, Canada. It is immediately upriver from Sand Island which is itself immediately upriver from Harsens Island; it includes two smaller islands, Anderson Island on the northwest, and "The Gold Coast" on the southwest. The island, which is accessible only via passenger ferry or by private watercraft, contains about 150 cottages.