Isle Royale National Park, Lake Superior

Isle Royale National Park is an island in northwest Lake Superior that preserves 132,018 acres of land-based wilderness that was federally designated on October 20, 1976. The park consists of one large island surrounded by about 400 smaller islands, and covers 850 square miles (2,210 sq km) including submerged land, which extends 4 1/2 miles out into the largest freshwater lake in the world. The wilderness island contains a roadless backcountry, which prohibits the use of all wheeled vehicles and devices (except wheelchairs). Visitors traveling to the island must arrive by boat or seaplane. Divers can visit 10 major shipwreck sites around the island. Divers must register at Houghton, Rock Harbor or Windigo visitor centers before diving. Discovery of artifacts should be reported to a park ranger but not removed.
Depths to: The 10 major shipwreck sites range in depths from 10 feet (3 m) to more than 200 feet (61 m) but most are in recreational-friendly depths of 30-60 feet (9-18 m).
Water temperature: At the surface water temperature rarely reaches 55 degrees Fahrenheit (13 degrees Celsius). Below the surface, divers can expect 34-37 F (1-3 C). A full wet suit is necessary and a dry suit is recommended.
Aquatic life: Include brown and rainbow trout, Pacific salmon, sea lamprey, rainbow smelt, alewife.
Fees: $4 per day for anyone using the park. Season passes cost $50.
On-site amenities: Information centers, ranger stations, trails, lookout towers, campsites.
More info: Visit nps.gov./isro/planyourvisit/scuba-diving.htm or call (906) 482-0984.
Open: April 16 to October 31. It is one of the few national parks to close during the winter.
Getting there: Departure information from Minnesota and Michigan are available at www.nps.gov/isro/planyourvisit/directions.htm.