Fourth Lake Millennium Trail is a 4.4 mile moderately trafficked out and back trail located near Lindenhurst, Illinois that features a lake and is rated as moderate. The trail offers a number of activity options and is accessible year-round.
cross country skiing
The preserve offers a short 0.3-mile grass loop trail with overlook, and a 2.7-mile gravel section of the Millennium Trail that stretches through Fourth Lake from just north of Rollins Road to Sand Lake Road where it connects to existing trail at Bonner Farm and McDonald Woods in Lindenhurst. Fourth Lake and its fen ecosystem are home to a variety of state threatened and endangered plant species and could provide habitat for the American bittern and various rails. Fens are rare, often sloping, wetlands that occur where mineral rich alkaline groundwater comes to the surface. Unlike bogs, fens have higher nutrient and mineral levels and sustain a more diverse plant and animal community. Fens are often covered by grasses, sedges, reeds and wildflowers. Considered a swale, rather than a kettle ecosystem, the fen is situated between two ridges of the Valparaiso Moraine. The fen drains south into Fourth Lake, which drains eastward via Mill Creek to the Des Plaines River.