Mackinac Island State Park, T.40N., R.3W., Mackinac County, Michigan; Cheboygan, Michigan, U.S.G.S. 30 × 60 minute series. Mackinac Island is located 3 mi (5 km) east of St. Ignace, Michigan, in the Straits of Mackinac (Fig. 1). Access to the Island from St. Ignace is provided by Arnold Transit or Star Lines from mid-April to late-December. From Mackinaw City, service is provided by Arnold Transit or Shepler’s Mackinaw Island Ferry from mid-May to mid-October. Service is at least hourly during the summer months. Air charter service is provided by Great Lakes Charters, St. Ignace, or Michigan Airways, Pellston. From...