Rockhounding in Custer County, CO: 215 USGS Mineral Sites (2026)

Check access before you go. Most sites listed here are old mines, quarries or prospects, and many are on private land or active mining claims. Get the landowner's permission, check the rules of the agency that manages any public land, and never enter mine workings. Locations are approximate.

Sketch map

Past ProducerProducerProspectOccurrenceStatus unknown

70 paw pins; nearby sites are grouped into one pin. Hover or tap a pin for the site name. 2 site(s) with USGS coordinates outside the outline are not pinned. County outline: US Census Bureau cartographic boundary file (2023). Locations approximate.

Woof’s favorite find

Geyser Mine

We picked it because its USGS record mentions 5 gem or collectible minerals (Quartz, Garnet, Gold, Agate, Silver) and 8 of our card minerals overall. No other named site here scores as high on both counts. USGS lists it as past producer for Lead, Silver. Minerals mentioned: Quartz, Garnet, Gold, Agate, Pyrite, Galena, Copper, Silver. Approx. location 38.139, -105.441. USGS record.

Ask first: a USGS record doesn’t mean you can visit. Find out who owns the land and get permission before collecting.

Field cards: what kind of sites?

119

Past Producer

Produced ore or material at some point in the past.

Prospect

Explored or test-dug, with no recorded production.

Occurrence

The mineral was noted here, without development.

Producer

Was producing when the record was made.

Unknown

Status not recorded.

Status terms come from USGS MRDS records.

Mineral cards

Silver
Mohs 2.5–3. Native silver tarnishes black. Mindat
132 sites
Galena
Mohs 2.5–2.75. Heavy, silvery lead ore that breaks into cubes. Mindat
89 sites
Pyrite
Mohs 6–6.5. Brassy “fool’s gold,” often cubic. Mindat
81 sites
Quartz
Mohs 7. Six-sided points; smoky quartz is NH’s state gem. Mindat
67 sites
Copper
Mohs 2.5–3. Native copper is soft and turns green as it weathers. Mindat
46 sites
Gold
Mohs 2.5–3. Soft, heavy and bright yellow; it doesn’t tarnish. Mindat
35 sites
Fluorite
Mohs 4. Cubes in purple, green or yellow; many glow under UV. Mindat
25 sites
Magnetite
Mohs 5.5–6.5. Black and strongly magnetic. Mindat
5 sites

Counts are sites whose USGS record mentions the mineral or commodity. Hardness from Mindat.

Minerals recorded here

Galena 67Chalcopyrite 45Thorite 45Sphalerite 33Pyrite 31Silver 19Tetrahedrite 19Barite 15Gold 12Stephanite 12Argentite 9Cerargyrite 8

Commodities

Silver 127Lead 70Thorium 42Copper 41Zinc 31Gold 30Barium-Barite 20REE 15Uranium 13Iron 11

Sites (first 40)

Site	Commodity	Minerals recorded	Status	Approx. location
Democrat Hill deposit	Potassium, Silver, Aluminum, Gold	Alunite, Diaspore, Kaolinite, Pyrite, Galena, Sphalerite	Past Producer	38.105, -105.361
Preston Gold Mine	Silver, Gold	Argentite	Past Producer	38.151, -105.451
Round Mountain Prospect	Silver, Gold	Argentite, Bromyrite, Cerargyrite, Chalcopyrite, Galena, Jarosite, Pyrite	Prospect	38.143, -105.423
Kate Mine	Silver	Argentite, Bromyrite, Cerargyrite, Chalcopyrite, Galena, Pyrite	Past Producer	38.145, -105.454
Twenty-Six Shafts	Silver	Argentite, Chalcopyrite, Galena	Past Producer	38.113, -105.333
Geyser Mine	Lead, Silver	Argentite, Chalcopyrite, Galena, Gold, Hessite, Polybasite, Pyrargyrite, Sphalerite, Tetrahedrite	Past Producer	38.139, -105.441
Maverick Mine	Zinc, Lead, Silver	Argentite, Chalcopyrite, Galena, Pyrite, Silver, Sphalerite, Stephanite, Tetrahedrite	Past Producer	38.102, -105.338
Nebraska Shaft	Silver	Argentite, Pyrite	Past Producer	38.112, -105.335
Summit Mine	Silver	Argentite, Pyrite, Galena, Chalcopyrite, Sphalerite	Past Producer	38.111, -105.334
Wet Mountain Mine	Barium-Barite	Barite	Past Producer	38.236, -105.253
Feldspar Mine	Barium-Barite	Barite	Producer	38.238, -105.252
Barrel Springs Mine	Barium-Barite	Barite	Past Producer	38.237, -105.329
Mystery Lode	Thorium	Barite, Chalcopyrite, Galena, Rhodochrosite, Sphalerite, Thorite	Occurrence	38.175, -105.294
Darby Extension	Thorium, REE	Barite, Chalcopyrite, Galena, Thorite	Past Producer	38.241, -105.367
Big Chief 1 Claim	Barium-Barite, Silver	Barite, Chalcopyrite, Galena, Thorite	Past Producer	38.249, -105.261
Lucky Find Claim	Barium-Barite, Thorium	Barite, Chalcopyrite, Thorite	Prospect	38.184, -105.331
General Ike Prospect	Thorium, Barium-Barite, REE	Barite, Galena, Gold, Silver, Thorite	Prospect	38.207, -105.330
Haputa Ranch	Gold, Thorium, REE, Barium-Barite, Lead	Barite, Galena, Thorite	Prospect	38.152, -105.275
Blue Bird Claim	Thorium, Barium-Barite	Barite, Thorite	Prospect	38.188, -105.293
Valley View Claim	Thorium, Barium-Barite	Barite, Thorite	Prospect	38.203, -105.321
Pine Tree Claim	Thorium	Barite, Thorite	Past Producer	38.187, -105.290
Hidden Valley Claims	Thorium, Barium-Barite	Barite, Thorite	Prospect	38.202, -105.319
Beardsley Deposit	Thorium, REE	Barite, Thorite	Past Producer	38.120, -105.322
Swartz Ranch	Vermiculite, Thorium, REE	Bertrandite, Thorite	Prospect	38.148, -105.332
Franklin Mine	Thorium, REE	Bornite, Galena, Thorite	Past Producer	38.174, -105.231
Damn Fool Claims	Uranium	Carnotite	Occurrence	37.957, -105.559
King Midas Claims	Uranium, Vanadium	Carnotite, Coffinite, Tyuyamunite, Uranophane	Past Producer	37.958, -105.559
Game Ridge Mine	Silver	Cerargyrite	Past Producer	38.106, -105.321
King of the Valley Mine	Silver	Cerargyrite	Past Producer	38.142, -105.446
Vanderbilt Mine	Silver, Lead	Cerargyrite, Cerussite	Past Producer	38.151, -105.439
Racine Boy Mine	Silver, Lead	Cerargyrite, Galena, Goethite, Jarosite	Past Producer	38.139, -105.439
Ophir Creek Claims	Lead, Gold, Silver	Cerargyrite, Gold	Prospect	38.036, -105.143
Boulder-Buffalo	Silver	Cerargyrite, Ocher, Psilomelane	Past Producer	38.141, -105.439
Oak Creek (Ilse) District	Lead	Cerussite, Phosgenite	Past Producer	38.197, -105.226
Hard Cash Mine	Silver	Chalcocite, Galena	Past Producer	38.114, -105.319
Sangre De Cristo Mine	Copper	Chalcopyrite	Past Producer	38.227, -105.674
Rita Alta Mine	Copper	Chalcopyrite	Past Producer	38.234, -105.680
Nightengale Claim	Thorium, REE	Chalcopyrite, Barite, Galena, Thorite	Prospect	38.124, -105.311
Invincible Shaft	Silver, Copper	Chalcopyrite, Covellite, Galena, Malachite, Pyrite, Silver, Stephanite, Tetrahedrite	Past Producer	38.108, -105.348
Pioneer Mine	Gold, Silver	Chalcopyrite, Covellite, Galena, Malachite, Pyrite, Silver, Stephanite, Tetrahedrite	Past Producer	38.110, -105.340

Nearby counties

Fremont County · Costilla County · Pueblo County · Huerfano County · Alamosa County

Colorado mineral guides

Back to all Colorado counties.

Is It Legal to Collect Rocks on Public Land? BLM, Forest Service and National Park Rules

How we built this page: we counted named sites in the USGS Mineral Resources Data System (MRDS) for this area, left out sand, gravel, crushed stone, clay pits and unnamed sites, grouped them by Census county, and linked every site to its USGS record. We did not visit these sites, and MRDS does not tell you who owns the land or whether collecting is allowed.

Source: USGS Mineral Resources Data System (MRDS). USGS ceased systematic updates to MRDS around 2011, so status and details may be out of date. Each site links to its USGS record.

Updated October 2026

Rockhounding in Custer County, Colorado

Sketch map

Geyser Mine

Field cards: what kind of sites?

Mineral cards

Silver

Galena

Pyrite

Quartz

Copper

Gold

Fluorite

Magnetite