Peterson Park: Petoskey Stone & Chert Rockhounding in Leelanau County, Michigan

Updated August 2026

Peterson Park is a mapped rockhounding spot in Leelanau County, Michigan. Reported finds include petoskey stone, chert, unakite, charlevoix stone. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Leelanau County
State: Michigan
Postcode: 49674
Coordinates: 45.15390, -85.64671

Geology at Peterson Park

This spot sits on Traverse Group, mapped as limestone that formed roughly 395 to 385 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: Traverse Group
Age: 395–385 Ma (Middle Devonian)
Rock types: limestone
Elevation: 640 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 Peterson Park

Best months: April to October. Typical highs run 76°F in midsummer and 29°F in midwinter, with winter lows near 19°F.

Climate normals: NOAA 1991-2020 monthlies, NORTHPORT 2W station (1 mi away).

Land & collecting status

Generally open to casual rockhounding

Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig.

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 Peterson Park

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 Peterson Park.

Peterson Park FAQ

Where is Peterson Park?+

Peterson Park is in Leelanau County, Michigan, at 45.15390, -85.64671.

What rocks and minerals can you find at Peterson Park?+

Peterson Park is reported to produce Petoskey Stone, Chert, Unakite, Charlevoix Stone.

Is collecting allowed at Peterson Park?+

Generally open to casual rockhounding. Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig. Always confirm current rules with the managing agency before a trip.

What tools should I bring to Peterson Park?+

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 Peterson Park?+

The most comfortable months at Peterson Park are April to October.

How do I get to Peterson Park?+

Open the directions link to navigate to 45.15390, -85.64671 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in Michigan

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Open Peterson Park on the map

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