Rockhounding in Wisconsin

Bayfield County

The Lake Superior shoreline of Bayfield County, along the State Highway 13 corridor between Port Wing and Cornucopia, is a classic stretch of public agate beach. Town and county beaches at Port Wing, Herbster, and Cornucopia present gravel and cobble that yield Lake Superior agates, jasper, and basalt, concentrated after storms. Collecting is legal on these municipal beaches, unlike the neighboring Apostle Islands National Lakeshore, where it is prohibited.

Agate, Jasper

Iron County

The Montreal River gorge below Saxon Falls exposes Keweenawan basalt whose gas cavities are lined with zeolite minerals. The Wisconsin Geological and Natural History Survey records prehnite and thomsonite here, along with calcite, epidote, laumontite, and chlorite in the amygdaloidal flows. The falls sit on a hydroelectric project with a public overlook and parking, so the loose float along the public river access is the practical collecting ground.

Calcite, Chlorite, Epidote, Laumontite

Jackson County

The reclaimed Jackson County iron mine, now the free Wazee Lake Recreation Area east of Black River Falls, is one of Wisconsin's premier metamorphic mineral localities. The Wisconsin Geological and Natural History Survey documents almandine garnet porphyroblasts up to 2 cm alongside staurolite, andalusite, kyanite, sillimanite, and magnetite in the mica schist and iron formation around the pit. Collecting is done on the waste-rock piles and schist exposures, since the open pit itself is now the deepest lake in the state.

Actinolite, Almandine, Andalusite, Biotite

Racine County

Quarry Lake Park in Racine exposes the Silurian Racine Formation dolomite, part of the reef complex recognized as among the first fossil coral reefs described in North America. The reef flank beds here yield crinoid columnals, corals, brachiopods, and bryozoans, documented by the Field Museum and Milwaukee Public Museum reef projects. The park is a public Racine County facility, unlike the active commercial quarries nearby that are closed to collectors.

Fossils, Calcite, Marcasite

Iowa County

The Wisconsin River gravel bars near Muscoda carry Lake Superior agates and quartz transported south by glacial outwash, giving the Driftless Area a rare source of free public collecting. Under Wisconsin's public trust doctrine, the beds of navigable rivers below the ordinary high-water mark are held open to the public, and surface-picking loose stones from sandbars is broadly permitted. Access is through public boat landings, with the exposed gravel bars richest at low summer water.

Agate

Douglas County

Wisconsin Point, a three-mile public sand and gravel spit at the mouth of Superior Bay, is the state's most accessible Lake Superior agate beach. The agates are wave and glacially transported nodules of banded chalcedony weathered from the billion-year-old Keweenawan basalts, and the strand line also yields jasper, drift copper, and basalt. The point is owned by the City of Superior and open to the public, with collecting best along the gravel lenses after storms and at low water.

Lake Superior Agate, Jasper, Copper, Basalt

Ashland County

Big Bay Town Park on Madeline Island gives collectors a Lake Superior beach reachable by the Bayfield ferry. The long pebble and sand beach along Big Bay yields Lake Superior agates, jasper, and basalt cobbles, some carrying zeolite and thomsonite amygdules. The town park is public and open to collecting, in contrast to the adjacent Big Bay State Park, where rock removal requires written state permission.

Lake Superior Agate, Jasper, Thomsonite, Basalt

Iron County

Saxon Harbor is Wisconsin's only county park on Lake Superior, set on Oronto Bay near the Michigan border. A 2020 reconstruction opened designated rock-picking beaches east and west of the harbor entrance, where collectors find Lake Superior agates, jasper, and occasional drift copper in the shoreline gravel. The park is a free Iron County facility with parking, boat launches, and beach access.

Lake Superior Agate, Jasper, Copper

Ozaukee County

Lime Kiln Park near Grafton preserves two small Silurian reefs in the walls of a former limestone quarry along the Milwaukee River. The Field Museum records favositid and halysitid corals, stromatoporoids, brachiopods, and nautiloid cephalopods in the exposed dolomite. The park is a free Ozaukee County facility with interpretive trails through the old quarry and kiln ruins.

Fossils, Coral, Crinoids, Dolomite

Iron County

The schist exposures near Powell, on the Manitowish Range, form one of Wisconsin's few good kyanite and staurolite localities. The Wisconsin Geological and Natural History Survey documents blue kyanite and staurolite porphyroblasts up to about 3 cm in mica schist with biotite, quartz, and oligoclase. The site lies in public forest country along State Highway 182, and regional gem and mineral clubs have run collecting trips here.

Kyanite, Staurolite, Almandine, Biotite