Green Bay National Wildlife Refuge

About Us

On February 21, 1912, President William Howard Taft established Green Bay National Wildlife Refuge, our nation’s 28th refuge and only the second refuge in the Great Lakes region. Located in Lake Michigan, off the tip of Wisconsin’s Door Peninsula, the refuge started as a mere 2-acre island that was originally named Green Bay Reservation. Today, this essential stopover habitat for birds and other migratory species consists of five islands and is framed by Wisconsin and Michigan.

The refuge is now made up of the following six units:

Hog Island, Wisconsin
Plum Island, Wisconsin
Pilot Island, Wisconsin
A 148-acre parcel of land on Detroit Island, Wisconsin
1,260 acres of St. Martin Island, Michigan
Rocky Island, Michigan

These islands act collectively as stepping stones for migrating birds, bats and butterflies as they cross along this section of the Niagara Escarpment – an outcropping of limestone that stretches in a wide arc from eastern Wisconsin through Michigan’s Upper Peninsula, across Ontario, Canada and on through the Niagara Falls in New York.

Long before European settlement in Wisconsin, several different Native American Tribes occupied and traversed where were historically called “the Potowatomi Islands.” Located in what is now northern Door County, Wisconsin and southern Delta County, Michigan, this archipelago enabled otherwise distant Tribes an opportunity for safer travel and trade among Lake Michigan’s treacherous waters.

The chain of islands sprinkled between peninsulas are valuable patches of habitat for a variety of migratory species during both the migration and the breeding season. Hog, Pilot and Rocky islands are valuable as colonial waterbird breeding, nesting and loafing sites. The location of these islands near forage fish habitat, combined with their remote and undisturbed condition, offer these species of migratory birds the necessary protected habitat. Habitat for colonial waterbirds has been under intense pressure on some Great Lakes islands as shoreline development continues.

Larger, forested islands also provide valuable feeding and resting stops for songbirds, bats and monarch butterflies migrating across open water. Habitat types differ from dense northern mesic forest, early successional forest and shrubby understory, to open habitat types of grassland, wetland and shoreline areas. Shoreline habitats on the islands range from sandy and silty areas to areas of exposed limestone bedrock, loose cobble-stone alkaline shoreline and globally rare alvar habitat containing specialized plants species.

Biologists and land managers have been roughing the waves and extreme weather of Lake Michigan to help colonial nesting waterbirds birds for more than 100 years, but the refuge boasts more than nesting birds. While they started with a small footprint that focused on bird conservation, botanists and other researchers from around the world have come to study the diverse plant life that has persisted here for millennia.

The Green Bay National Wildlife Refuge is managed by staff at the Horicon National Wildlife Refuge Complex in Mayville, Wisconsin.

Hog Island

Hog Island was set aside by Executive Order 1487 in 1912 as a preserve and breeding ground for native birds, making it one of the oldest national wildlife refuges in the nation! As many bird species were being extirpated due to the plume trade and market hunting of the era, Hog Island was home to some of the only remaining nesting habitat for herons and egrets. Today that habitat continues to be preserved, and herons and egrets continue to return to the island year after year to raise young.

In 1970, the United States Congress designated Hog island as part of the Wisconsin Islands Wilderness Area. Along with nearby islands of Gravel Island National Wildlife Refuge this wilderness area wilderness area
Wilderness areas are places untamed by humans. The Wilderness Act of 1964 allows Congress to designate wilderness areas for protection to ensure that America's pristine wild lands will not disappear. Wilderness areas can be part of national wildlife refuges, national parks, national forests or public lands managed by the Bureau of Land Management.

Learn more about wilderness area is one of the smallest wilderness areas in the country, at 29 acres. The prime management consideration of the wilderness status was the continued protection of nesting birds by limiting access to the islands during the breeding seasons. For this reason, these wilderness islands are closed to public visitation. The wilderness designation provides an additional level of protection on the islands and boaters are asked to stay at least a quarter mile offshore so as not to endanger the nesting areas.

Plum and Pilot Islands

Plum and Pilot islands were added to the refuge on October 17, 2007. Jurisdiction of the islands was transferred from the U.S. Coast Guard to the U.S. Fish and Wildlife Service through Public Land Order 7681 to become part of Green Bay National Wildlife Refuge, with a purpose to protect native and migratory bird habitat and endangered species habitat within the Great Lakes Basin ecosystem. The islands were excess to the Coast Guard’s needs and therefore made available to other federal agencies.

Today, Plum and Pilot islands continue to conserve and protect the vital habitats for fish, plants, and wildlife. The islands have also played a significant role in the maritime history of Wisconsin and are home to buildings found on the National Register of Historic Places. Green Bay National Wildlife Refuge works in partnership with the Friends of Plum and Pilot Island to meet historic preservation goals for these structures, and to continue tell the stories of the sites.

Plum Island is open for public access Memorial Day through Labor Day during daylight hours only. Pilot Island remains closed to public access to meet the primary conservation purpose of the site for migratory and colonial nesting birds, and as related to the State of Wisconsin’s terms for the 2007 lands transfer.

Rocky Island

Rocky Island, located near the Garden Peninsula of the upper peninsula of Michigan, was added to the refuge on August 14,2014. This 10-acre island was donated to The Nature Conservancy in 1986, and transferred to the U.S. Fish and Wildlife Service to protect native and migratory bird and endangered species habitat within the Great Lakes Basin ecosystem.

Rocky Island is located approximately two miles off Michigan’s Garden Peninsula in close proximity to Little Summer Island.

Rocky Island is closed to all public use to protect those species and their habitat.

St. Martin Island

St. Martin Island was added to the refuge on September 21, 2015. This large, forested island protects native and migratory bird habitats, as well as vital endangered species habitat for plants such as the Canada yew and dwarf lake iris. Other species of concern found on the island include American sea rocket, dune goldenrod, white camas and climbing fumitory.

St. Martin Island is part of the Niagara Escarpment and has significant bluffs, which have rare native snails and plants associated with them. In addition to the bluffs, the island also supports forests, wetlands and an extensive cobblestone beach.

The Nature Conservancy purchased the majority of St. Martin Island - 1,244 acres - from the Fred Luber family in 2013, and an additional 36 acres from David Uihlein, Jr. in 2014. The remainder of the island, which consists of 57 acres, and the historic St. Martin Island lighthouse are owned by the Little Traverse Bay Band of Odawa Indians.

Funding for the acquisition of St. Martin Island was provided by the Luber and Uihlein families, who generously donated a portion of the value of their lands to The Nature Conservancy, other private gifts to The Nature Conservancy, grants from the North American Wetlands Conservation Act program and the Great Lakes Restoration Initiative, and settlement funds administered by the Fox River / Green Bay Natural Resource Trustee Council.

St. Martin Island is located about five miles from Washington and Rock islands at the tip of Wisconsin’s Door Peninsula.

Public access to St. Martin Island is prohibited to protect critical habitat and historic sites, limit invasive species invasive species
An invasive species is any plant or animal that has spread or been introduced into a new area where they are, or could, cause harm to the environment, economy, or human, animal, or plant health. Their unwelcome presence can destroy ecosystems and cost millions of dollars.

Learn more about invasive species transport, and public safety concerns.

Detroit Island

The Detroit Island Unit was added to the refuge in on March 28, 2019. Funding for the acquisition was provided by settlement funds administered by the Fox River / Green Bay Natural Resource Trustee Council.

This 148-acre unit is open for public access during daylight hours, Memorial Day through Labor Day. The unit is also open for deer hunting during State of Wisconsin seasons and hunters should be aware of private lands that border the refuge property.

Our Mission

The mission of the National Wildlife Refuge System is to administer a national network of lands and waters for the conservation, management and, where appropriate, restoration of the fish, wildlife and plant resources and their habitats within the United States for the benefit of present and future generations of Americans.

Our History

430 million years ago – The Niagra Escarpment begins to form under the sea as a dolomitic limestone. For millions of years that limestone bedrock experienced uplift and erosion, glaciation and glacial melt to form these Lake Michigan stepping stone islands that stretched between Wisconsin’s Door Peninsula and Michigan’s Garden Peninsula.
12,000 years ago – Paleo-Indian people are the first inhabitants of the region and move frequently through the area. The Potawatomi, Ho-Chunk, Menominee, Ojibwe and Sauk Native nations inhabited the region for millennia before the arrival of European explorers and settlers.
1600s A.D. – The lands surrounding the refuge saw the first known European explorers, including Jean Nicolet, Father Marquette and Robert de LaSalle. By the 1650s, the fur trade era brought European settlers to the area. Trader’s canoes and boats increase in numbers on Lake Michigan.
1830 – Overhunting of fur-bearing animals brings the fur trade to a grinding halt in the area. Traders are forced to look farther west. By 1850 the region’s fur trade was over.
Mid-1800s – The timber industry begins to take off in the region. Areas closest to rivers and lakes are clear-cut, and trees as large as four feet across and thousands of years old are harvested to feed western expansion. Rafts of timber move across Lake Michigan, boats transport cordwood to port towns and sawmills expand coastal towns of the region. Fishing industry also gains momentum, and a fish camp is established on St. Martin Island.
1848 – Wisconsin becomes the thirtieth state in the Union on May 29, 1848.
December 11, 1848 – The federal government withdrew an island known as "Plum" by Executive Orders and reserved it for federal lighthouse purposes.
1849 - The first lighthouse and keeper’s dwelling are built on Plum Island and known as the Port du Mort Light Station.
May 28, 1858 – The federal government withdrew an island known as "Pilot" by Executive Orders and reserved it for federal lighthouse purposes.
1858 - The light on Plum Island is determined to be too far west to aid shipping, so it is abandoned, and Pilot Island Light is built.
Late 1800s – Market hunting and the plume trade decimate bird populations across the nation. Many bird species normally found in the Lake Michigan area are hunted nearly to extinction. Unregulated hunting and fishing negatively impact fish and wildlife populations throughout the United States and territories.
1871 – The U.S. Commission on Fish and Fisheries is established to respond to the dramatic decline in the nation’s fisheries stocks.
1885 – The Bureau of Biological Survey is established to study and map the nation’s faunal resources.
1890 – Due to increasing shipping traffic in the Port des Morts and prompted by a number of wrecks in the passage, the Lighthouse Board requests a $21,000 congressional appropriation to establish a pair of range lights on Plum Island.
1891 – The Lighthouse Board requests funding for the St. Martin Island lighthouse to mark the Poverty Island Passage. Funds are approved in 1893.
1895 – Congress appropriates the necessary funds for Plum Island’s navigational aids, and the United States Life-Saving Service hires Marinette contractor C.J. Olson to build a “Duluth style” lifesaving station on the north-eastern side of Plum Island. The lifesaving station is built on the north-eastern side and begins operations April 1, 1896.
1896 – The Plum Island range lights, steam siren fog signal, and brick keeper’s dwelling are built to create the light station on the south-western side of the island. Work on the light station is completed on December 4, 1896.
1889 – The last camps close and families leave St. Martin Island as all profitable timber is harvested and fish populations decline.
Early 1900s – Logging in the region experiences a steep decline as forests are completely cut over, and the most usable and profitable timber is gone. Immigrants move to the region and convert the barren forests into farmland.
1900 – The Lacey Act bans interstate trade in illegally obtained wildlife.
1903 – The first national wildlife refuge national wildlife refuge
A national wildlife refuge is typically a contiguous area of land and water managed by the U.S. Fish and Wildlife Service  for the conservation and, where appropriate, restoration of fish, wildlife and plant resources and their habitats for the benefit of present and future generations of Americans.

Learn more about national wildlife refuge is established by President Roosevelt at Pelican Island in Florida. Work finally begins on building the St. Martin Island lighthouse, and the station is completed in 1904.
February 21, 1912 – Green Bay National Wildlife Refuge was established by President Taft at Hog Island under Executive Order 1487. The refuge thereby sets aside one of the few remaining nesting sites for egrets and herons on Lake Michigan after near-extirpation from unregulated hunting.
1915 – President Taft merges the U.S. Life-Saving Service and U.S. Lighthouse Service to create the U.S. Coast Guard.
1918 – The Migratory Bird Treaty Act is passed, providing significant protections for migratory birds.
1939 – The U.S. Coast Guard fully takes over operations of the Plum Island range lights and operations shift from the light keeping station to the lifesaving station on the north side of the island. Range lights become automated, the keeper’s quarters are boarded up and a watch room is added to the fog signal building.
1940 – The U.S. Fish and Wildlife Service is established after the Department of Interior merges the Bureau of Biological Survey and Bureau of Fisheries.
1962 – The Pilot Island light is decommissioned by the U.S. Coast guard, its light is automated, and the fog signal discontinued. The keeper’s quarters and fog signal building are both shuttered. Rachel Carson’s Silent Spring is published and introduces the world to the harm of widespread DDT use on bird species, including many that had been extirpated from the Lake Michigan ecosystem for decades.
October 23, 1970 – Public Law 91-504 designated the Hog Island of Green Bay National Wildlife Refuge as part of the Wisconsin Islands Wilderness and includes Gravel Island National Wildlife Refuge’s Gravel and Spider islands. The islands remain closed to public access and a quarter mile buffer is added to keep watercraft distant to the nesting bird habitats.
1973 – The Endangered Species Act, referred to as ESA, is passed by Congress. The ESA is designed to prevent future wildlife extinctions. It protects both endangered and threatened plants and animals and the critical habitat necessary for their survival. A truly pioneering piece of legislation, the ESA was the most comprehensive wildlife protection anywhere in the world.
1980 – The St. Martin Island lighthouse is automated by the U.S. Coast Guard. The Luber family purchases the island for private use.
1983 – The Pilot Island light is added to the National Register of Historic Places.
October 17, 2007 – Plum and Pilot islands were added to the refuge by Public Land Order 7681, with a conservation purpose to protect native and migratory bird habitat and endangered species habitat within the Great Lakes Basin ecosystem. The Friends of Plum and Pilot Island organization is established and works in partnership with the refuge to preserve the sites and tell the stories of those two important maritime sites.
2010 – Plum Island’s lifesaving and light keeping stations are added to the National Register of Historic Places.
August 14, 2014 – Rocky Island was acquired from The Nature Conservancy, pursuant of the Fish and Wildlife Act of 1956.
September 21, 2015 – 1,260 acres of St. Martin Island are officially acquired as part of the Green Bay National Wildlife Refuge. The remainder of the island, which consists of 57 acres and the historic lighthouse, are owned by the Little Traverse Bay Band of Odawa Indians.
March 28, 2019 – 148 acres were acquired on Detroit Island.
Today – Green Bay National Wildlife Refuge is made up of more than 1,730 acres across the six units. The refuge continues to conserve and protect fish, wildlife, plants and their habitats as one of more than 565 refuges across the United States and its territories. The entire National Wildlife Refuge System manages more than 150 million acres of habitat - the largest and most effective wildlife habitat program in the world. The refuge system is a great ongoing scientific experiment to protect at least a small percentage of the planet where wildlife can survive and thrive.