Use a Dedicated Rockhound Map
Generic Google Maps won't show you where crystals hide. Dedicated rockhound maps like the We Lick Rocks dig sites map overlay GPS coordinates for known gem locations on top of public land boundaries — so you can see exactly where you're allowed to dig.
Check BLM and National Forest Land
Bureau of Land Management (BLM) land is your best friend. Most BLM areas allow casual collection of up to 25 lbs of rocks per day for personal use at no cost. Download the BLM map layers or check our regulations page for your state.
Use Topo Maps to Read the Geology
Minerals concentrate where geological forces meet — fault lines, volcanic flows, and ancient streambeds. USGS topo maps (free at usgs.gov) show elevation changes that hint at exposed rock formations. Look for areas where a creek cuts through a hillside.
Mining Claim Databases
The MRDS (Mineral Resources Data System) is a free USGS database of known mineral localities. Search by state and mineral type to find coordinates for historic mine sites — many of which sit on public land and still produce great specimens.
Talk to Locals and Rock Clubs
The fastest way to find secret spots is word of mouth. Join a local gem and mineral club — most states have dozens. Members often share GPS waypoints, field trip schedules, and insider knowledge that never makes it online.