Rockhounding in Cook County, Minnesota

4 mapped rockhounding spots in Cook County. Most commonly produces lintonite, chalcocite, chalcopyrite, chlorastrolite.

Cook County rockhounding photos

Representative spot and material photos from this county, shown where verified public image records are available.

1 photo

Grand Marais harbor, lighthouse, and Artists Point on Lake Superior, Cook County, Minnesota — Grand MaraisCook County, Minnesota

Minerals reported in Cook County

Lintonite2
Chalcocite1
Chalcopyrite1
Chlorastrolite1
Lake Superior Agate1
Pyrite1
Thomsonite1
Thomsonite Nodules1

Standout in Cook County

Hand-picked spot in Cook County, chosen for unusual mineralogy or documented public access. Each card opens the full coordinates and access notes.

Top pick
Grand Marais
Public
Cook County
The Cook County shore around Grand Marais holds Minnesota's best thomsonite, a zeolite that filled gas cavities in the billion-year-old North Shore basalt flows and weathers out as rounded nodules with concentric green, pink, and white eyes. Good Harbor Bay is the most productive public thomsonite beach in the state, and the same lava flows yield lintonite, a green massive variety, alongside Lake Superior agate. Collecting is best after storms, when wave action turns fresh gravel onto the beach.
Lintonite, Thomsonite

Spots in Cook County

Spot	Minerals	Coordinates	Access
Arrowhead ParkNaniboujou Trail	Lake Superior Agate	47.8150, -90.0508	Public
Grand MaraisHarbor View Trail	Lintonite Thomsonite	47.7446, -90.3531	Public
Pigeon Point	Chalcocite Chalcopyrite Pyrite	48.0030, -89.4972	Public
Thomsonite BeachMN 61	Chlorastrolite Lintonite Thomsonite Nodules	47.7278, -90.4584	Public

Neighboring counties in Minnesota

Adjacent rockhounding counties, ranked by how close their centroids sit to Cook County. A natural extension if Cook County is already on your trip plan.

Across the state line from Cook County

Rockhounding counties in neighboring states within driving range. Geology rarely respects state borders — these are often the closest mapped spots you can reach without going deeper into Minnesota.

Cook County FAQ

Where can I rockhound in Cook County, Minnesota?+

RockHoundR tracks 4 rockhounding spots in Cook County. Each entry below has coordinates, mineral notes, and access type. Always confirm local rules before collecting.

What rocks and minerals are common in Cook County?+

Spots in Cook County most often produce Lintonite, Chalcocite, Chalcopyrite, Chlorastrolite, Lake Superior Agate. Individual spots can vary widely.

Are these Cook County rockhounding spots on public land?+

Most spots in this list are tagged public, but access can change with seasons, claims, and local closures. Always verify before driving out — links in the app open the right BLM, USFS, or county pages.

Plan a Cook County rockhounding trip

Open RockHoundR to see these spots on the map alongside land overlays, weather, geology, and your saved finds.