Mazonia State Fish and Wildlife Area (Mazon Creek Fossils)
Approximate — check official site before visiting
World-famous Mazon Creek fossil collecting area in Grundy County, known for Pennsylvanian-age plant and animal fossils preserved in ironstone concretions. Includes the Tully Monster (Tullimonstrum gregarium), the Illinois state fossil. A day permit is required and available from the park office. Collecting restricted to March 1 - September 30. Excavations and commercial collecting prohibited. Spoil piles from historic coal mining yield the concretions.
🪨 What You Can Find Here
Fossils
From shark teeth in Florida to dinosaurs in Montana, the US offers world-class fossil hunting for all skill levels.
Also found at:
Ironstone Concretions
Also found at:
- No other locations listed yet
Tully Monster Fossils
Also found at:
- No other locations listed yet
📍 Nearby Locations in Illinois
Apple River Canyon State Park
Apple River, Illinois · State Park
Scenic state park in northwest Illinois with limestone bluffs exposing geodes and calcite veins. Collecting limited — check with park office.
Illinois Fluorite District
Rosiclare, Illinois · Public Land
Historic Illinois-Kentucky fluorspar district. Mine dumps produce blue, purple, and yellow fluorite crystals. Once the world's largest fluorite produc...
Sparland Fluorspar Area
Sparland, Illinois · Public Land
Central Illinois exposures for fluorite and calcite crystals. Part of the Illinois-Kentucky fluorspar district extension.
Warsaw Area Geodes
Warsaw, Illinois · Public Land
Road cuts and creek beds in the Warsaw area produce excellent geodes (Keokuk-type) along the Mississippi River valley.
The Rock and Soul
Utica, Illinois · Fee Dig
Rock shop with gem mining sluicing experience and geode cracking. Formerly Illinois Valley Gems and Minerals. Located in the heart of the Illinois Val...
Nick's Geodes
Hamilton, Illinois · Fee Dig
Private geode collecting operation on a creek-loaded property between Nauvoo, IL and Keokuk, IA. Visitors pay per bucket and dig geodes from the creek...
⛏️ Recommended Gear
Make the most of your visit to Mazonia State Fish and Wildlife Area (Mazon Creek Fossils) with the right equipment.
Rock Hammer
The most essential rockhounding tool. Choose a hammer with both a flat striking face and a pointed pick end.
Typical: $25-45
Safety Glasses
Mandatory protective gear. Rock chips fly unpredictably when hammering.
Typical: $10-20
Chisel Set
Cold chisels in 3-4 sizes for precise extraction from matrix rock.
Typical: $15-30
Geologist's Pick
A heavier crack hammer for splitting hard rock. Essential for hard rock mining areas.
Typical: $35-60
Sifting Screen
Stackable mesh screens for sifting gravel and dirt. Essential for gem and fossil hunting.
Typical: $20-40
UV Flashlight
Long-wave UV light for finding fluorescent minerals and Yooperlites.
Typical: $15-35