Where to Find Prehnite in Michigan
Michigan has 6 mapped collecting spots that report prehnite, spread across 2 counties. The largest share sits in Keweenaw County with 4 spots. 2 of the spots are on land mapped as publicly accessible.
Spot list checked against source data on April 1, 2026.
Map of 6 prehnite collecting spots in Michigan
Best counties for prehnite in Michigan
Ranked by the number of mapped prehnite spots. County links open the full rockhounding page for that county.
Every prehnite spot we track in Michigan
Sorted by county. Coordinates open in Google Maps.
| Spot | County | Minerals | Coordinates | Access |
|---|---|---|---|---|
| Calumet Waterworks Park | Houghton County | 47.2741, -88.5298 | Check locally | |
| McClain State ParkBear Lake Road | Houghton County | 47.2368, -88.6147 | Permission | |
| Cliff Mine | Keweenaw County | 47.3729, -88.3131 | Check locally | |
| Cliff North | Keweenaw County | 47.3764, -88.3158 | Check locally | |
| Gratiot River County Park | Keweenaw County | 47.3437, -88.4525 | Public | |
| High Rock Bay | Keweenaw County | 47.4233, -87.7152 | Public |
Before you go
Read the prehnite identification guide so you know what a keeper looks like in the field: Prehnite in the encyclopedia.
Prehnite in Michigan FAQ
Where can you find prehnite in Michigan?+
The mapped spots concentrate in Keweenaw County and Houghton County. Every spot on this page appears on the map above with coordinates and access notes.
How many prehnite spots are mapped in Michigan?+
6 spots across 2 counties. The RockHoundR app keeps the same spots on an offline map with public land overlays, geology layers, and your saved finds.
Is it legal to collect prehnite in Michigan?+
Hand collecting of common rocks and minerals in small amounts for personal use is generally allowed on BLM and U.S. Forest Service land, with limits set by the local field office. National parks, most state parks, and tribal land are closed to collecting. 2 of the 6 mapped spots here sit on land marked public. Always confirm current rules with the managing agency before you dig.
