Decades ago, the 288-acre property now known as Theodore Marsh was a wetland. But dumping of construction debris and invasion of non-native species worked to alter the ecology of the land. Today, the preserve is the focus of a multi-year restoration to return the land to its original character. When the wetlands return, habitat for a wide range of species will attract wildlife to this preserve located in the middle of neighborhoods and bordered by the busy streets of Theodore and Gaylord.

Visitors to this site can enjoy the use of a playground, open play field, and picnic shelter, which is available for reservation for large groups.

The Rock Run Trail, a 9-mile asphalt trail suitable for all non-motorized, non-equestrian use, runs through the preserve and is part of the 16-mile Rock Run Trail/Joliet Junction Trail loop. This loop travels southeast to the I&M Canal State Trail, west to the I&M Canal Access, north past Joliet Junior College, Hammel Woods, Black Road Access, and Paul V. Nichols Access, and back to Theodore Marsh.

Photograph Courtesy of Glenn P. Knoblock