Fourth Lake Fen Nature Preserve
Rate this placeLast Updated: December 5, 2025
Fourth Lake Fen Nature Preserve is located in Lake County, Illinois, and is a 135-acre nature preserve that showcases one of the few remaining natural fens in the state.
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Summary
A fen is a type of wetland that is fed by mineral-rich groundwater and supports a diverse array of plant and animal life.
There are several good reasons to visit Fourth Lake Fen Nature Preserve, including the opportunity to see rare and endangered plant species, such as the Eastern Prairie Fringed Orchid and the Purple Milkweed. The preserve also offers a unique opportunity to observe a wide variety of bird species, including the Sandhill Crane and the Great Blue Heron.
Visitors to Fourth Lake Fen can take a leisurely walk along the boardwalk, which winds through the wetland and offers stunning views of the surrounding landscape. Other points of interest include the observation deck, which provides a panoramic view of the fen, as well as the interpretive signs that provide information about the ecology and history of the area.
Interesting facts about Fourth Lake Fen Nature Preserve include its geological origins, which date back to the last ice age, and the fact that the preserve was once used for agriculture and grazing before being restored to its natural state.
The best time of year to visit Fourth Lake Fen Nature Preserve is during the summer months when the orchids and other wildflowers are in bloom, and the bird activity is at its peak. Visitors should also be aware that the preserve is open from dawn to dusk, and pets are not permitted on the boardwalk or in the fen.
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Park & Land Designation Reference
Large protected natural areas managed by the federal government to preserve significant landscapes, ecosystems, and cultural resources; recreation is allowed but conservation is the priority.
State Park
Public natural or recreational areas managed by a state government, typically smaller than national parks and focused on regional natural features, recreation, and education.
Local Park
Community-level parks managed by cities or counties, emphasizing recreation, playgrounds, sports, and green space close to populated areas.
Wilderness Area
The highest level of land protection in the U.S.; designated areas where nature is left essentially untouched, with no roads, structures, or motorized access permitted.
National Recreation Area
Areas set aside primarily for outdoor recreation (boating, hiking, fishing), often around reservoirs, rivers, or scenic landscapes; may allow more development.
National Conservation Area (BLM)
BLM-managed areas with special ecological, cultural, or scientific value; more protection than typical BLM land but less strict than Wilderness Areas.
State Forest
State-managed forests focused on habitat, watershed, recreation, and sustainable timber harvest.
National Forest
Federally managed lands focused on multiple use—recreation, wildlife habitat, watershed protection, and resource extraction (like timber)—unlike the stricter protections of national parks.
Wilderness
A protected area set aside to conserve specific resources—such as wildlife, habitats, or scientific features—with regulations varying widely depending on the managing agency and purpose.
Bureau of Land Management (BLM) Land
Vast federal lands managed for mixed use—recreation, grazing, mining, conservation—with fewer restrictions than national parks or forests.
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