The McHenry County Conservation District is responsible for the conservation of the Fen Nature Preserve and Exner Marsh. For more information about these preserves, contact the McHenry County Conservation District at (815) 338-6223.

Fen Nature Preserve

The Lake in the Hills Fen is a 260-acre nature preserve covered with over 400 species of native plants and wildflowers (more than 40 of which are classified as uncommon, rare, or endangered), over 60 species of birds, rare insects, and geological features called "hanging fens" left from the Ice Age.

Exner Marsh

The Exner Marsh offers 1.3 miles of hiking trails. Along these trails, you can stop for a scenic view of the 116 acres of Illinois State Nature Preserve. After your hike, have a picnic lunch at the shelter on Lakewood.