Wilderness State Park #26: Stromatolite & Jacobsville Sandstone Rockhounding in Emmet County, Michigan

Updated August 2026

Wilderness State Park #26 is a mapped rockhounding spot in Emmet County, Michigan. Reported finds include stromatolite, jacobsville sandstone, garnet schist, lake superior agate, hematite, and more. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Paid / fee dig
County: Emmet County
State: Michigan
Coordinates: 45.75747, -84.96873

Geology at Wilderness State Park #26

This spot sits on Bois Blanc Formation, mapped as limestone that formed roughly 420 to 395 million years ago. Chert and agate nodules typically form inside carbonate rock like this and weather out as tough, waxy lumps in soils and creek beds.

Mapped unit: Bois Blanc Formation
Age: 420–395 Ma (Early Devonian)
Rock types: limestone
Elevation: 580 ft

Geologic mapping via Macrostrat and the underlying state geological survey maps (CC BY 4.0). Bedrock at the surface can vary within a mapped unit.

Best time to visit Wilderness State Park #26

Best months: April to October. Typical highs run 75°F in midsummer and 27°F in midwinter, with winter lows near 14°F.

Climate normals: NOAA 1991-2020 monthlies, CROSS VILLAGE 1E station (8 mi away), adjusted for elevation.

Land & collecting status

Pay-to-dig site

This is a fee-dig location. Hours, prices, and what you can keep vary by operator. Call ahead before driving out.

Public-land rules vary by agency, season, and field office. The RockHoundR app pulls live BLM, USFS, NPS, and tribal overlays so you can see exactly which agency manages the ground at this spot.

Sources & verification

Spot details combine the public RockHoundR location dataset, normalized mineral labels, agency land-status checks in the app, and community submissions. Coordinates are approximate until verified in the field.

State guidance last verified: April 1, 2026

Michigan DNR — Rockhounding rules
Michigan Geological Survey
Isle Royale National Park — Rules
Community submissions reviewed against published agency rules

Found at Wilderness State Park #26

Each chip opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.

Nearby rockhounding spots

Other rockhounding spots within driving distance of Wilderness State Park #26.

Wilderness State Park #26 FAQ

Where is Wilderness State Park #26?+

Wilderness State Park #26 is in Emmet County, Michigan, at 45.75747, -84.96873.

What rocks and minerals can you find at Wilderness State Park #26?+

Wilderness State Park #26 is reported to produce Stromatolite, Jacobsville Sandstone, Garnet Schist, Lake Superior Agate, Hematite, Gastropod.

Is collecting allowed at Wilderness State Park #26?+

Pay-to-dig site. This is a fee-dig location. Hours, prices, and what you can keep vary by operator. Call ahead before driving out. Always confirm current rules with the managing agency before a trip.

What tools should I bring to Wilderness State Park #26?+

Most agate and jasper is surface float: bring a spray bottle, a pick or small shovel, and a sturdy bag. Wet stones show their banding and translucence.

When is the best time to visit Wilderness State Park #26?+

The most comfortable months at Wilderness State Park #26 are April to October.

How do I get to Wilderness State Park #26?+

Open the directions link to navigate to 45.75747, -84.96873 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in Michigan

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Open Wilderness State Park #26 on the map

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