Two campers died on Lake Superior’s remote Isle Royale. Here’s what we know.

Earlier this week, the National Park Service reported that two campers were found dead at a remote backcountry campground on Isle Royale — an island on Lake Superior that is a two-hour ferry ride from Grand Portage, Minn.

Since then, authorities have released few details about the deaths. Here is what to know about the investigation and the island, one of the most inaccessible wilderness areas in the Midwest and best known for being home to significant populations of wolves and moose.

The National Park Service said it received two separate calls Sunday about the deaths at the remote South Lake Desor Campground, which is about 11.5 miles from the Windigo Visitor Center on the island’s west side — a primary destination for travel from Grand Portage.

The campground is off the Greenstone Ridge trail, which runs the length of the island to the other main park entrance, Rock Harbor.

Authorities have identified the people who died and have notified family, but have not publicly released the names or causes of death. They have also said there is no known threat to the public.

The National Park Service did not return a call seeking comment on a timeline for releasing more information.

Isle Royale is in Keweenaw County, Mich., but the National Park Service handles most incidents there. The Detroit Free Press has reported that the FBI has been involved in the investigation.

The park is mainly one large island but is surrounded by more than 450 smaller islands. The main island is known as a rugged backpacking destination, and is about 50 miles long and 9 miles wide.

The island was part of the ancestral land of the Grand Portage Band of Lake Superior Chippewa. Indigenous people mined for copper on the island thousands of years ago, and more recently people mined copper there in the late 1800s and logged in the 1900s.

Now, Isle Royale is known for its moose and wolves, the latter of which were reintroduced in 2018 starting with four animals captured at the Grand Portage Reservation. Last year, Michigan Tech researchers found there were 30 wolves on the island and 840 moose.

The number of moose on the island has fluctuated, at times numbering in the thousands but also plummeting in some years from many factors, including tick infestations. The National Park Service says there are beavers, red fox, otters, American martens and bats on the island.

Isle Royale can only be reached by boat or seaplane.

Grand Portage Isle Royale Transportation Lines ferries passengers across Lake Superior in two boats from Grand Portage with several stops around the island, and it typically takes 1 ½ to 2 hours from Grand Portage to reach the first stop.

From Michigan, visitors can charter a seaplane from Hubbell, Mich. There are also ferries from Houghton and Copper Harbor, Mich., that take between 3 ½ to 6 hours to reach the island.

About 21,000 people visited the island last year, making it one of the least-visited national parks.

Isle Royale is about 20 miles east of Minnesota but 55 miles west of Michigan’s Upper Peninsula. So why is it part of Michigan?

The short answer is that Michigan became a state more than 20 years before Minnesota, allowing Michigan to claim the island first. Isle Royale is also closer to Canada than the U.S., but American negotiators at the end of the Revolutionary War persuaded Britain to draw the border north of the island.

In July, John Nousaine, a 70-year-old man from Superior, Wis., on a recreational diving expedition, died while scuba diving at least 100 feet below the surface of Lake Superior near the stern of the Emperor shipwreck. The steel bulk freighter sank in 1947. The Keweenaw County Sheriff worked alongside the National Park Service during the investigation.