RockWoof
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

Unnamed Location (Occurrence)Unnamed Bentonite Occurrence (Occurrence)Unnamed Quarry + 2 more nearby (Past Producer)Unnamed Bentonite Occurrence + 1 more nearby (Occurrence)Unnamed Bentonite Occurrence + 1 more nearby (Occurrence)Unnamed Bentonite Occurrence (Occurrence)Unnamed Bentonite Occurrence + 1 more nearby (Occurrence)Unnamed Bentonite Occurrence + 1 more nearby (Occurrence)Unnamed Coal Mine (Prospect)Hardin Bentonite (Past Producer)Unnamed Bentonite Occurrence (Occurrence)Wyotona Mining Co. Property (Prospect)Bentonite Occurrence + 1 more nearby (Occurrence)Bentonite Prospect + 1 more nearby (Occurrence)Unnamed Bentonite Occurrence (Occurrence)
Past ProducerProducerProspectOccurrenceStatus unknown
15 paw pins; nearby sites are grouped into one pin. Hover or tap a pin for the site name. County outline: US Census Bureau cartographic boundary file (2023). Locations approximate.

Field cards: what kind of sites?

17
Occurrence

The mineral was noted here, without development.

4
Past Producer

Produced ore or material at some point in the past.

2
Prospect

Explored or test-dug, with no recorded production.

Status terms come from USGS MRDS records.

Minerals recorded here

No individual minerals are listed in these records.

Commodities

Bentonite 18Flagstone 2Calcium 1Silica 1Uranium 1

Sites

SiteCommodityMinerals recordedStatusApprox. location
Unnamed Bentonite OccurrenceBentonite—Occurrence45.221, -107.771
Unnamed Bentonite OccurrenceBentonite—Occurrence45.228, -107.816
Unnamed QuarryFlagstone—Past Producer45.297, -107.919
Lime DepositCalcium—Past Producer45.326, -107.959
Unnamed Bentonite OccurrenceBentonite—Occurrence45.535, -107.394
Unnamed Bentonite OccurrenceBentonite—Occurrence45.578, -107.906
Unnamed Bentonite OccurrenceBentonite—Occurrence45.248, -107.825
Hardin BentoniteBentonite—Past Producer45.727, -107.604
Bentonite ProspectBentonite—Occurrence45.652, -107.390
Unnamed Bentonite OccurrenceBentonite—Occurrence45.667, -107.422
Unnamed QuarryFlagstone—Past Producer45.327, -107.939
Wyotona Mining Co. PropertyBentonite—Prospect45.001, -107.536
Unnamed Bentonite OccurrenceBentonite—Occurrence45.378, -107.566
Unnamed Bentonite OccurrenceBentonite—Occurrence45.226, -107.712
Unnamed Bentonite OccurrenceBentonite—Occurrence45.562, -107.830
Unnamed Coal MineBentonite—Prospect45.144, -107.679
Silica Sand OccurrenceSilica—Occurrence45.273, -107.782
Unnamed Bentonite OccurrenceBentonite—Occurrence45.167, -107.712
Unnamed Bentonite OccurrenceBentonite—Occurrence45.304, -107.785
Unnamed Bentonite OccurrenceBentonite—Occurrence45.560, -107.804
Bentonite OccurrenceBentonite—Occurrence45.728, -107.420
Unnamed Bentonite OccurrenceBentonite—Occurrence45.751, -107.403
Unnamed LocationUranium—Occurrence45.439, -108.122

Fossil collections

The Paleobiology Database lists 65 fossil collection records in Big Horn County. These are research records, not public dig sites.

Nearby counties

Carbon County · Yellowstone County · Rosebud County · Treasure County · Stillwater County

Montana mineral guides

Back to all Montana counties.

Related articles

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