Where to Find Thundereggs
15 mapped thundereggs spots across 4 regions. Pick a region for its local guide, or browse every spot by country below. Thundereggs is reported at multiple rockhounding spots across the United States. The map below shows where collectors most often find it on legal public ground.
Top regions for thundereggs
United States
15 spots · 4 regionsMap showing where to find thundereggs, with 15 mapped spots
Every mapped thundereggs spot
Thundereggs rockhounding FAQ
Where is the best place to find thundereggs?+
Oregon, Arizona, California have the highest concentrations of thundereggs in this list. Quality and access vary by area, so open the linked region pages for a detailed view.
How many thundereggs rockhounding spots does RockHoundR track?+
15 mapped spots across 4 regions. The app keeps these on a map alongside your private finds.
Can I legally collect thundereggs on public land?+
In the U.S., casual hand collecting of common rocks and minerals like thundereggs 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. Rules differ by country and region, so always check with the managing agency before a trip.
How do I identify thundereggs in the field?+
Field identification of thundereggs 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 thundereggs on the map
Open RockHoundR to see these spots on a real map with public land overlays and trip-planning details.
