Green Park: Charlevoix Stone & Honeycomb Coral Rockhounding in Ontonagon County, Michigan

Updated August 2026

Green Park is a mapped rockhounding spot in Ontonagon County, Michigan. Reported finds include charlevoix stone, honeycomb coral, rhyolite, quartz, lake superior agate, and more. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Ontonagon County
State: Michigan
Coordinates: 46.83896, -89.43599

Geology at Green Park

This spot sits on Oronto Group; Freda Sandstone, mapped as shale, siltstone, and arkose that formed roughly 1600 to 1000 million years ago. Sedimentary layers like these are where fossils are typically preserved, and fresh exposures after rain or in active cuts tend to produce best.

Mapped unit: Oronto Group; Freda Sandstone
Age: 1600–1000 Ma (Mesoproterozoic)
Rock types: shale, siltstone, and arkose
Elevation: 610 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 Green Park

Best months: April to October. Typical highs run 80°F in midsummer and 26°F in midwinter, with winter lows near 9°F.

Climate normals: NOAA 1991-2020 monthlies, ONTONAGON 6 SE station (11 mi away), adjusted for elevation.

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 Green 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 Green Park.

Across the state line from Green Park

Green Park is close enough to the Michigan border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Green Park FAQ

Where is Green Park?+

Green Park is in Ontonagon County, Michigan, at 46.83896, -89.43599.

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

Green Park is reported to produce Charlevoix Stone, Honeycomb Coral, Rhyolite, Quartz, Lake Superior Agate, Yooperlite.

Is collecting allowed at Green 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 Green Park?+

A rock hammer, a cold chisel, safety glasses, and newspaper or foam for wrapping finds cover most fossil ground. A trowel and a sieve help in soft exposures.

When is the best time to visit Green Park?+

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

How do I get to Green Park?+

Open the directions link to navigate to 46.83896, -89.43599 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in Michigan

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Open Green Park on the map

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