Protecting Historic Structures from Wildfire in the Midwest

In Spring 2022, wildland firefighters from the Great Lakes Fire Management Zone, based at Indiana Dunes National Park, focused efforts to create “defensible space” around historic structures at both Saint Croix National Scenic Riverway, located along the Wisconsin and Minnesota border, and at Sleeping Bear Dunes National Lakeshore in Northern Michigan.

Creating defensible space involves reducing the amount of vegetation (hazardous fuels) and opening up, or clearing, the space immediately adjacent to structures. In a wildland fire, that excess vegetation is the fuel for the fire. By removing the excess fuel from an area 30 feet around the structure, it creates space for firefighters to work to suppress a fire. Thinning out the vegetation, or fuels, from 30ft to 100ft away from the structure reduces the intensity of any wildfires as they approach a structure. This tiered approach to protecting structures is referred to as FireWise landscaping.

Over the course of a few weeks, wildland firefighters conducted hazardous fuels reduction work around four historic cabins at Saint Croix National Scenic Riverway, and 47 structures at Sleeping Bear Dunes National Lakeshore. Both historic and non-historic administrative structures at both parks received this much needed defensible space. Fire crews spent 12 days on North and South Manitou Islands at Sleeping Bear Dunes National Lakeshore. The islands do not have any permanent fire protection staff, so it was important to create FireWise landscaping to reduce the possibility of wildfires from becoming structure fires. The Manitou islands once housed US Lifesaving Stations and are historically important to the settlement of the Great Lakes area by French Fur Traders and loggers. Native Americans have a cultural and historic connection to the islands as well. North and South Manitou are the bear cubs referred to in the Legend of Sleeping Bear.

Thanks to the many hours of labor performed by the NPS wildland firefighters of the Great Lakes Fire Management Zone this year; the maintenance staff and volunteers of both Saint Croix National Scenic Riverway and Sleeping Bear Dunes will now be able to maintain the defensible space around these park structures via their regularly scheduled mowing and maintenance activities.

The mission of the National Park Service is to “preserve unimpaired the natural and cultural resources and values of the National Park System for the enjoyment, education, and inspiration of this and future generations.” One of the ways the NPS protects and preserves our cultural values is by reducing the threat of wildfire to historic structures, while preserving cultural landscapes.

For information on how you can create Defensible Space around your home, go to: NFPA - Preparing homes for wildfire

Barn on the Bournique Farm, North Manitou Island.

Left image
Before picture of the barn at the the Bournique Farm, North Manitou Island.
Credit: NPS

Right image
After picture of the barn at the the Bournique Farm, showing defensible space created to protect the structure from wildfire.
Credit: NPS

This photo comparison shows the barn at the Bournique Farm on North Manitou Island before and after hazardous fuels reduction was conducted around it. The historic structure now has approximately 30ft of cleared space around it with additional thinned out vegetation beyond that. This cleared space will help to protect the building from any wildfires.