Marengo Ridge Conservation Area is one of McHenry County’s most popular and treasured areas. It contains over 818 acres of oak and hickory woodlands interspersed with spruce, aspen, ash, and sumac groves. The Marengo Ridge, from which the site derives its name, was formed by the retreating Wisconsin glacier. Stretching 40 miles long and 3 miles wide, the Marengo Ridge moraine is one of the steepest and most vertical in Illinois, rising to 1,050 feet above sea level. This glacial feature was created around 24,000 years ago. Be sure to dress for the weather, wear sturdy shoes, and bring your own water.