Where to Find Thomsonite in the United States
8 mapped thomsonite spots across 4 U.S. states. Thomsonite is reported at multiple rockhounding spots across the United States. The map below shows where collectors most often find it on legal public ground.
Map showing where to find thomsonite across the United States, with 8 mapped spots
Top states for thomsonite
States ranked by number of thomsonite spots in our database. States in bold link to a focused thomsonite-in-state list.
Every thomsonite spot we track
Sorted by state and county. Coordinates open in Google Maps.
| Spot | County | Minerals | Coordinates | Access |
|---|---|---|---|---|
| McClain State ParkBear Lake Road | Houghton County |
| 47.2368, -88.6147 | Public |
| Keweenaw Point | Keweenaw County |
| 47.4079, -87.7115 | Public |
| Lake Superior BeachLakeshore Road | Ontonagon County |
| 46.8713, -89.3352 | Public |
| Grand MaraisHarbor View Trail | Cook County |
| 47.7446, -90.3531 | Public |
| Beaver BayClub Road | Lake County | 47.2573, -91.2958 | Public | |
| Little Marais RiverMN 61 | Lake County |
| 47.4144, -91.0993 | Public |
| Columbia River shoreNorthwest Reeder Road | Columbia County | 45.7993, -122.7926 | Check locally | |
| Near Saxon FallsSaxon Falls Road | Iron County |
| 46.5356, -90.3787 | Public |
Thomsonite rockhounding FAQ
Where is the best place to find thomsonite in the U.S.?+
Michigan, Minnesota, Oregon have the highest concentrations of thomsonite in this list. Each state's quality and access varies — open the linked state pages for a detailed view.
How many thomsonite rockhounding spots does RockHoundR track?+
8 mapped spots across 4 states. The app keeps these on a map alongside your private finds.
Can I legally collect thomsonite on public land?+
Casual hand collecting of common rocks and minerals like thomsonite is allowed on most BLM and U.S. Forest Service land, with daily and annual limits set by the local field office. National parks, most state parks, and tribal land are off-limits. Always check with the managing agency before a trip.
How do I identify thomsonite in the field?+
Field identification of thomsonite comes down to color, hardness, fracture, and luster. The RockHoundR app links to geology details for each spot to help narrow down what you might be picking up.
Hunt thomsonite on the map
Open RockHoundR to see these spots on a real map with public land overlays and trip-planning details.
