The Robert O. Cook Memorial Arboretum is owned by the city but is managed by the Janesville Public School District and is the site of the Janesville Schools Outdoor Laboratory (JSOL).  A large portion of the Arboretum is a beautiful mature forest, and it also includes a prairie, marsh and wetlands, making it an excellent place for birding. Many species of native trees, plants, birds and other wildlife can be found here. Approximately eight miles of trails wind throughout the Arboretum, some with interpretive trail markers, and the Ice Age National Scenic Trail runs through it. The Arboretum is an excellent place to snowshoe. An interactive map of the trails is available on the website. Leashed pets are allowed September 16 to May 14 only.