55,566 annual visits
7,716 overnight visits
Although there is no full-time naturalist on staff at the park, interpretive programs are offered occasionally throughout the year.
Glendalough is home to abundant populations of white-tailed deer, raccoon, red fox, and smaller mammals. The park also offers excellent birdwatching for a variety of species of prairie, wetland, and hardwood forest birds. An active eagle nest and fresh beaver cuttings can be viewed from the park trails, and loons are common on the park's lakes. Wildlife observation blinds have been constructed and binoculars and birding kits are available for loan at the park.
Originally acquired by Ezra Valentine in 1903 as a summer retreat, the land was sold in 1928 to F.E. Murphy, owner of the Minneapolis Tribune Company. Murphy expanded the property and started a private game farm there. In 1941, the property as well as the Tribune newspaper was sold to Cowles Media Company. The Cowles family continued to operate the game farm and add more land to the property, which they used as a private family and corporate retreat. During the 1950s, former presidents Dwight Eisenhower and Richard Nixon were among the many notable guests at Glendalough. On Earth Day, 1990, this largely natural and undeveloped property was donated to The Nature Conservancy. On June 10, 1992, the deed was transferred to the Minnesota Department of Natural Resources for use as a state park.
Leaf Hills, like those in another state park, Glacial Lakes, is a term often used to describe the hills evident in Otter Tail County. The hills were created by glacial ice and meltwater deposits of sand gravel. Although the highest hills extend to 1800 feet above sea level, the hills in the park are much lower. The outwash drift in the Glendalough area is mainly sandy loam.
One of the last large tracts of undeveloped lakeshore in western Minnesota (9.2 miles) lies within the park. The gently rolling topography is an excellent example of original landscape transition from prairie to northern hardwoods. This hilly, lake-strewn, and partially wooded countryside is an excellent setting for recreational activities.