Check out this link for detailed list of grant resources

The Natural Resources Foundation.

The Friends of Wisconsin State Parks works closely with The Natural Resources Foundation. Specifically, we introduce our Friends Groups to grant opportunities offered by The Natural Resources Foundation of Wisconsin. The Natural Resources Foundation of Wisconsin funds projects that have a significant and positive impact on Wisconsin’s lands, waters, and wildlife, and that connect people to Wisconsin’s natural wonders.

The Natural Resources Foundation have invested nearly $7 million in public and private conservation efforts—from funding statewide wildlife monitoring programs to creating butterfly gardens at local schools, and from building trails at state parks to helping recover the federally endangered whooping crane.
Please click the following link for information:

https://www.wisconservation.org/grant-programs/

The David and Joyce Weizenicker Fund for State Parks

The David and Joyce Weizenicker Fund for State Parks was established to support projects on Wisconsin State Park properties that facilitate accessibility for senior citizens, especially trail development, maintenance and restoration, and the development and maintenance of rest stops, including benches, overlooks, and interpretive signage. Grants range from $500 to $5,000.

Photo: David and Joyce Weizenicker pictured at Kinnickinnic State Park at the unveiling of a new trail funded in part by the David and Joyce Weizenicker Fund for State Parks. Photo by Caitlin Williamson

Eligibility:
Applicant must be a Friends group of a Wisconsin State Park property, with a formal agreement in place with the Wisconsin Department of Natural Resources.
A 1:1 match is required. Match may include cash or in-kind support such as volunteer hours or donated materials.
Project expenses may not have been incurred prior to submitting the application. More information....