For more than 12,000 years, people have traveled on the Great Lakes, from Native American dugout canoes to wooden sailing craft and steel freighters, and thousands of ships have made millions of voyages on these inland seas. During the last 150 years, Great Lakes shipping grew enormously and remains critical to the national economy, but fire, ice, collisions, and storms claimed hundreds of vessels, including pioneer steamboats, wooden schooners, and steel freighters. Today, the 4,300-square-mile Thunder Bay National Marine Sanctuary protects 200 shipwrecks in Lake Huron's clear, fresh water, preserving the Great Lakes and their rich history through research, education, and community involvement so future generations can enjoy these underwater treasures. The sanctuary also supports public access through diving, snorkeling, paddling, lighthouse visits, glass-bottom boat and kayak tours, seasonal mooring buoys that make wrecks safer to visit and help prevent anchor damage, and the Great Lakes Maritime Heritage Trail, which connects visitors with Lake Huron's maritime past.