CHESTERTON, Ind. — Authorities plan four prescribed fires at Indiana Dunes National Park this spring, totaling more than 900 acres.

Authorities said prescribed fires are used to restore the park.

Exact dates have not been announced yet. Humidity and wind speed and direction must be ideal to complete each planned fire, the National Park Service said in a statement.

The National Park Service said one of the fires is planned for about 300 acres of prairie and woodland in the east half of the park. The three other fires are planned in the west end of the park.

The northwest Indiana park includes 15 miles of Lake Michigan shoreline and 15,000 acres of beaches, woods, prairies and marshes.

A map of the areas included in the prescribed fires is available at the National Park Service website.

Residents of Lake and Porter counties can sign up for free notices about the prescribed fires at www.smart911.com or check the Indiana Dunes National Park’s Facebook page.