Established on September 1, 2015, it is the largest freshwater marine protected area in the world. The conservation area extends 140 kilometers eastward from Thunder Bay, from Thunder Cape in the west, at the tip of Sleeping Giant Provincial Park, to Bottle Point in the east, and stretches southward to the Canada-US border, linking with Isle Royale National Park. The Nipigon River and Lake Nipigon lie to the north.

Proposals to protect the area were first suggested in the mid-1990s, and formal plans were first announced in 2002.

The marine conservation area was proposed after discussion with provincial and First Nations representatives. The First Nations in the area, represented by Wilfred King, the regional grand chief of the northern Superior region, endorsed the proposal once they were satisfied that it respected the Robinson Superior Treaty of 1850.

Lake Superior National Marine Conservation Area covers roughly 10,000 km2 of the lakebed, its overlaying fresh water, and associated shoreline on 60 km2 of islands and mainland. The area is home to numerous species including herons, peregrine falcons, and bald eagles. The spawning and schooling waters of deep cold water fish, such as whitefish, lake herring, walleye, and lake trout will be protected by this zone. Caribou foraging and calving areas are located on shore. Lake Superior is home to about 70 fish species.

The official designation prevents resource extraction or other operations which may damage the aquatic or terrestrial ecosystems in the conservation area. However, per the agreement with the First Nations, it does not exclude all commercial marine activity, such as shipping, and commercial and sport fishing.

According to Wikipedia