Thunder Bay National Marine Sanctuary in Alpena

Thunder Bay National Marine Sanctuary protects “Shipwreck Alley,” a 450-square-mile stretch of Lake Huron near Alpena that’s packed with nearly 200 sunken historic vessels.

Storms, thick fog, shipping congestion, and underwater hazards led to a high number of wrecks here, with some dating back to the mid-1800s up to the mid-1900s.

Cold freshwater keeps these schooners, steamers, and freighters remarkably intact, and you can see them for yourself via glass-bottom boat tours, dive trips, or exhibits inside Alpena’s Maritime Heritage Center.