Where: Minnesota · North America · approx. 47.83, -90.17 (vicinity only)
Why this spot: Rockhounding locality: thomsonite in basalt amygdules, North Shore
What turns up: thomsonite, Lake Superior agate, basalt
Access: Permission required.
The beach adjoining the historic Thomsonite Beach Inn is private (guests only); collect thomsonite only at the public Good Harbor Bay roadside outcrop/public shore access or with owner permission.
Open in Mudlark Map →
Satellite view, historic-map overlays, tide/flow context and field notes are in the app. Exact research detail is part of Pro.
Pins are approximate by design. This page is historical research, not permission to dig. Check ownership and local law first.