Rockhounding in Jefferson County, CO: 218 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

72 paw pins; nearby sites are grouped into one pin. Hover or tap a pin for the site name. 9 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

Ralston Buttes District

We picked it because its USGS record mentions 4 gem or collectible minerals (Quartz, Gold, Fluorite, Silver) and 7 of our card minerals overall. That ties with 1 other site(s), so we broke the tie by mine status (past producers first), then USGS record quality, then name. USGS lists it as producer for Uranium. Minerals mentioned: Quartz, Gold, Pyrite, Galena, Fluorite, Copper, Silver. Approx. location 39.844, -105.281. 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?

Producer

Was producing when the record was made.

Past Producer

Produced ore or material at some point in the past.

Occurrence

The mineral was noted here, without development.

Unknown

Status not recorded.

Prospect

Explored or test-dug, with no recorded production.

Status terms come from USGS MRDS records.

Mineral cards

Feldspar
Mohs 6–6.5. Blocky crystals with flat cleavage faces. Mindat
105 sites
Quartz
Mohs 7. Six-sided points; smoky quartz is NH’s state gem. Mindat
65 sites
Mica
Mohs 2–3. Peels into thin, flexible, shiny sheets. Mindat
47 sites
Fluorite
Mohs 4. Cubes in purple, green or yellow; many glow under UV. Mindat
38 sites
Copper
Mohs 2.5–3. Native copper is soft and turns green as it weathers. Mindat
27 sites
Pyrite
Mohs 6–6.5. Brassy “fool’s gold,” often cubic. Mindat
25 sites
Garnet
Mohs 6.5–7.5. Usually deep red, round many-faced crystals. Mindat
18 sites
Beryl
Mohs 7.5–8. Six-sided crystals; aquamarine and emerald are beryl. Mindat
16 sites

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

Minerals recorded here

Quartz 37Muscovite 22Microcline 20Pitchblende 16Beryl 15Fluorite 13Feldspar 12Chalcopyrite 11Galena 11Pyrite 11Sphalerite 11Mica 10

Commodities

Feldspar 95Quartz 43Mica 35Uranium 34Beryllium 25Fluorine-Fluorite 22REE 20Copper 16Gemstone 16Gold 11

Sites (first 40)

Site	Commodity	Minerals recorded	Status	Approx. location
Coors Pegmatite	Feldspar, Mica	Albite, Cleavelandite, Microcline	Past Producer	39.700, -105.373
Burroughs Feldspar Mine	Feldspar, Beryllium, Mica	Allanite, Beryl, Columbite, Euxenite, Gadolinite, Microcline, Monazite, Muscovite, Pyrochlore, Tantalite, Xenotime	Past Producer	39.681, -105.323
Roscoe Gulch Pegmatites	Beryllium, Mica, Feldspar	Allanite, Beryl, Microcline, Monazite, Muscovite	Past Producer	39.747, -105.373
Shuttle Run Mine	Feldspar, Quartz	Allanite, Gadolinite, Quartz	Past Producer	39.374, -105.200
Madonna No. 2	Quartz, Feldspar	Allanite, Gadolinite, Quartz, Microcline	Past Producer	39.377, -105.195
Madonna No. 3	REE, Quartz, Feldspar	Allanite, Gadolinite, Quartz, Microcline	Past Producer	39.377, -105.196
Big Bertha Mine	Quartz, Feldspar	Allanite, Xenotime	Past Producer	39.339, -105.218
Orthite #1 & Sunset Groups	REE, Zirconium	Allanite, Zircon	Occurrence	39.338, -105.251
Thomas-Union Lodes	Quartz, Feldspar, Mica, Garnet, Gemstone	Apatite, Garnet, Muscovite, Quartz	Producer	39.541, -105.195
Silver Glen Ranch Pegmatite	Mica, Feldspar	Bertrandite, Beryl, Cleavelandite, Columbite, Microcline, Microlite, Monazite, Thorite	Past Producer	39.667, -105.303
Elledge	Beryllium	Beryl	Occurrence	39.791, -105.324
Bigger Mica Mine	Feldspar, Mica, Beryllium	Beryl, Bismuthinite, Bismutite, Cassiterite, Columbite, Microcline, Monazite, Muscovite	Past Producer	39.565, -105.215
Wasson Pegmatite	Beryllium, Feldspar, Mica	Beryl, Columbite, Euxenite, Microcline, Muscovite, Tantalite	Past Producer	39.703, -105.315
Tall Timber Group	Mica, Beryllium, Feldspar	Beryl, Columbite, Muscovite, Tantalite	Past Producer	39.646, -105.273
Buckman Ranch Pegmatite	Iron, Beryllium, Gemstone, Quartz, Garnet, Mica, Feldspar	Beryl, Feldspar, Garnet, Magnetite, Mica, Quartz, Tourmaline	Occurrence	39.582, -105.242
Cressman Gulch	Beryllium, Mica, Feldspar	Beryl, Feldspar, Muscovite	Producer	39.790, -105.250
Roscoe Beryl Prospect	Mica, Feldspar	Beryl, Gadolinite, Monazite, Muscovite, Xenotime	Past Producer	39.737, -105.358
Little Abner Pegmatite	Beryllium, REE, Feldspar	Beryl, Microcline	Past Producer	39.766, -105.349
Centennial Cone Prospect	Beryllium	Beryl, Microcline, Monazite, Muscovite, Quartz	Producer	39.754, -105.358
Cressmans Gulch Prospect	Feldspar, Beryllium	Beryl, Microcline, Muscovite	Past Producer	39.786, -105.256
Grover Winsor Pegmatite	Niobium (Columbium), Tantalum, REE, Feldspar, Mica, Beryllium	Beryl, Monazite, Muscovite	Producer	39.719, -105.455
Ladwig-Grosso Pegmatite	Beryllium, Mica	Beryl, Muscovite, Quartz	Past Producer	39.796, -105.271
Fred Pierce Ranch	Feldspar, Gemstone, Mica, Quartz	Biotite, Feldspar, Quartz, Tourmaline	Producer	39.777, -105.305
Susy Belle	Feldspar, Mica, Quartz, Fluorine-Fluorite, Gemstone	Biotite, Fluorite, Quartz, Topaz	Occurrence	39.381, -105.214
Lone & Lonesome Lodes	Mica, Fluorine-Fluorite, Gemstone	Biotite, Fluorite, Topaz	Producer	39.336, -105.418
Iowa Gulch	Quartz, Feldspar, Mica, Gemstone, Garnet, Iron	Biotite, Garnet, Magnetite, Microcline, Muscovite, Plagioclase, Quartz, Tourmaline	Occurrence	39.589, -105.230
Seven Hills-Yetter Ranch Pegmatite	Feldspar, Mica, Quartz, Garnet, Gemstone	Biotite, Garnet, Microcline, Muscovite, Quartz, Tourmaline	Occurrence	39.661, -105.324
Hiwan Ranch	Feldspar, Mica, Quartz, Garnet, Gemstone	Biotite, Garnet, Microcline, Plagioclase, Quartz, Tourmaline	Producer	39.719, -105.380
Ralston Buttes District	Uranium	Bismuth, Bornite, Chalcanthite, Chalcocite, Coffinite, Covellite, Galena, Jordisite, Marcasite, Molybdenite, Niccolite, Pyrite, Pyrrhotite, Silver, Sphalerite, Uranophane	Producer	39.844, -105.281
Ramstetter Ranch Prospect	Beryllium	Bismuthinite, Bismutite, Chrysoberyl, Microcline, Muscovite, Quartz	Occurrence	39.791, -105.314
Union Pacific Shaft	Uranium, Copper	Bornite, Chalcocite, Chalcopyrite, Pitchblende, Sphalerite, Tennantite	Occurrence	39.770, -105.266
North Star Mine	Copper	Bornite, Chalcocite, Covellite, Malachite, Pitchblende, Uranophane	Past Producer	39.861, -105.298
Mena Mine	Uranium	Bornite, Chalcocite, Covellite, Molybdenite, Niccolite, Pyrite, Silver, Sphalerite, Uraninite, Pitchblende	Past Producer	39.854, -105.302
Billiken and Black Knight Lodes	Uranium, Copper	Bornite, Chalcopyrite, Cuprite, Pitchblende, Pyrite, Tenorite, Torbernite, Uranophane	Occurrence	39.467, -105.219
Ladwig Group	Uranium	Bornite, Covellite, Pitchblende, Pyrite, Torbernite, Uranophane	Occurrence	39.770, -105.270
Pallaro Lease	Uranium	Carnotite	Occurrence	39.633, -105.167
Unnamed Silver Occurrence	—	Cassiterite, Molybdenite	Occurrence	39.173, -105.378
Bankers Lode Claim	Copper, Uranium	Chalcocite	Occurrence	39.891, -105.343
Augusta Mine	Copper, Silver, Fluorine-Fluorite	Chalcocite, Fluorite, Sphalerite	Past Producer	39.617, -105.318
Unnamed Cu Prospect	Copper	Chalcocite, Malachite	Occurrence	39.874, -105.366

Fossil collections

The Paleobiology Database lists 54 fossil collection records in Jefferson County. These are research records, not public dig sites.

Nearby counties

Denver County · Gilpin County · Clear Creek County · Arapahoe County · Boulder 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 Jefferson County, Colorado

Sketch map

Ralston Buttes District

Field cards: what kind of sites?

Mineral cards

Feldspar

Quartz

Mica

Fluorite

Copper

Pyrite

Garnet

Beryl