Matthiessen State Park was named for Frederick William Matthiessen, a prominent industrialist and philanthropist from LaSalle. He originally purchased the land near the end of the 19th Century and developed it as a privately owned park for many years. Mr. Matthiessen employed about 50 people to construct trails, bridges, stairways and check dams. The area was originally referred to as “Deer Park,” in reference to the large deer population. The original 176-acre park consisted primarily of a long narrow canyon with a small stream flowing through it. At that time these formations were called “dells,” a name that has stayed with the park. After Matthiessen’s death, the park was donated to the State of Illinois, which opened it as a public park. In 1943, the state renamed the park in honor of Matthiessen. Since then, the park has grown to 1,938 acres and includes much of the significant natural areas along the main dell, some former prairie land, and some forest land south of the original park.