It may seem strange to name a hilly and forested park after a fish but there once were plenty of trout to be found here. In 1870, Elgin dentist Philemon B. Pratt began breeding fish in ponds fed by natural springs flowing out of the hillside. The locals recognized this swampy area of white cedars as unique but they probably had no idea how geologically rare it was. The cold spring water, percolating through the underground gravel deposits, make this place a biological rarity known as a fen. This special habitat supports a variety of rare plants and invertebrates.

Dr. Pratt bottled water from the springs for sale and developed the area closest to the river into a picnic grove. The spot was ideally suited along the rail line which brought tourists out from Chicago. The picnic grove grew into an amusement park, complete with a roller coaster and paddle boats and other attractions. On summer weekends crowds of more than one thousand visitors were not uncommon.

The City of Elgin purchased the property in 1923 and '24 and turned it into a botanical garden. In 1933, a tornado ripped through the park and severely damaged it. The poor economy of the Great Depression left the city with no resources to rebuild. Construction of the toll road in 1959 sliced off 12 acres of land. More recently, the bike path and other improvements have helped preserve this special place for public enjoyment.