The mining camps layer is built into the map. Run a search — try the free demo first, no account.
The source is the USGS Mineral Resources Data System, a national record of mineral occurrences, prospects and mines. The full file runs to over 300,000 records worldwide and includes a great deal that is no use to a detectorist — active operations, gravel pits, stone quarries and mineral occurrences nobody ever dug.
Filtered to United States sites that are past producers of metal — meaning something was actually extracted and the workings are now abandoned — it comes to 44,677:
They are heavily concentrated in the West — California, Nevada, Colorado, Arizona and Alaska carry the bulk — but Missouri's lead belt and the Appalachian copper and gold districts put real numbers in the East too.
This is the single most useful idea in this guide. The dot in the database is a working — a shaft, an adit, a placer claim. Standing on it puts you on waste rock, which is the least productive ground in the district.
The people lived near it, and their choice of where was governed by things you can see in terrain data:
So when you see a cluster of workings, look downslope, at the nearest flat bench beside the nearest creek. That is your search centre.
Cabin platforms. On a slope, building anything flat means cutting into the hill and piling the spoil on the downhill side. That leaves a distinctive shelf — flat, rectangular, with a cut bank behind it. They are very hard to see on the ground under brush and very obvious in a Local Relief Model. A row of them along a contour is a camp.
The dump. Downhill, downwind, over the nearest edge. Tin cans, bottle glass and stove parts, and in a mining camp a notably high proportion of dropped coins, because these were cash economies.
Tailings and waste piles. Large, smooth, unnaturally uniform mounds with a flat top or a fan shape. Useful as landmarks — they mark the workings so you can orient from them — but not places to detect.
The road. Mining roads were cut for loaded wagons, so they hold a steady grade and switchback rather than running straight up. A switchbacking cut that leads to nothing is leading to something that was there.
Worth knowing before you build a plan around it: only 6,731 of the 44,677 records carry any date at all. "Past producer" means abandoned. It does not tell you whether that happened in 1874 or 1974, and a 1970s exploration adit is a very different afternoon from a gold-rush camp.
Where the record has a first-production or discovery year, the popup shows it. Where it doesn't, the district's history is the shortcut — a state geological survey bulletin or a county history will usually date a whole district in one go, and that is close enough to decide whether to walk it.
Coordinate precision varies for the same reason. Some entries are surveyed; others were derived from a section centre on an old report. Treat the dot as approximate and search around it.
Turn on the ghost towns layer at the same time and the map starts answering questions on its own.
A vanished town sitting inside a cluster of workings is a mining camp, and the two layers together give you both halves — the government's record of where people lived, and the record of what they were digging. That combination dates the site, tells you the population was transient and carrying cash, and separates the living ground from the working ground.
Workings with no vanished town near them usually mean the men walked in from somewhere that still exists, or camped rough and left less. Still worth looking, but expect thinner material.
Open shafts. Abandoned mine workings kill people every year. Vertical shafts get covered by brush, snow and rotten timber, and a covered shaft looks like ground. Never walk a mine site alone, never approach an opening, and treat any unexplained depression as a hazard rather than a feature.
Claims are property. An abandoned mine is not necessarily abandoned land. Many sites sit on active mining claims, which are private rights even on public ground, and taking material from one is theft rather than detecting. Others are on federal land where the rules differ by agency, and a site old enough to be interesting is often old enough to be protected as an archaeological resource.
Lidarman flags candidates on National Park Service and other federal land automatically, but it cannot see mining claims. Check before you go — see permission and legal basics.
All 44,677 abandoned metal mines are on the map — gold, silver, copper and the rest.
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