An executive order in 1913 declared Hog Island a national preserve for the benefit of native birds.

Gravel Island National Wildlife Refuge was created under the same executive order.

On October 17, 2007, Pilot and Plum Islands were officially added to the Green Bay National Wildlife Refuge.

[4] Green Bay National Wildlife Refuge contains a variety of plants native to the area.

[9] This plant was functionally extirpated on St. Martin's Island because of the introduction of white-tailed deer and their appetite for this shrub.

The refuge was established first for the purpose of conserving native birds of the Great Lakes Basin.

No development has occurred on Hog Island due to its small size, remoteness, and landing difficulties.

[9] Smallmouth bass are commonly found in the waters northwest of Plum and Pilot Islands.

[4] This article incorporates public domain material from websites or documents of the United States Fish and Wildlife Service.