Tres Hermanas Mts: Dumortierite & Hydrozincite Rockhounding in Luna County, New Mexico
- Minerals reported
- 6
- Elevation
- 4,650 ft
- Best months
- September to May
Tres Hermanas Mts is a mapped rockhounding spot in Luna County, New Mexico. Reported finds include dumortierite, hydrozincite, pyrolusite, quartz, smithsonite, and more. Below: coordinates, access notes, nearby spots, and trip-planning links.
Plan your visit
Generally open to casual rockhounding
- County
- Luna County
- State
- New Mexico
- Nearest road
- cdt
- Coordinates
- 31.93075, -107.72552
Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.
Land & collecting status
Generally open to casual rockhounding
Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig.
Access note: BLM records active mining claims in this area. Collecting from inside an active claim needs the claim holder's permission.
Public-land rules vary by agency, season, and field office. The RockHoundR app pulls live BLM, USFS, NPS, and tribal overlays so you can see exactly which agency manages the ground at this spot.
Best time to visit Tres Hermanas Mts
Comfortable months (45 to 90°F highs)
Best months: September to May. Typical highs run 94°F in midsummer and 57°F in midwinter, with winter lows near 29°F. Summer heat here is intense, so carry more water than you think you need and work the early morning.
Climate normals: NOAA 1991-2020 monthlies, COLUMBUS station (9 mi away), adjusted for elevation.
Geology at Tres Hermanas Mts
This spot sits on Hueco Formation or Group, mapped as limestone and shale that formed roughly 300 to 285 million years ago. Carbonate rock like this dissolves and weathers readily, so fresh road cuts, quarries, and creek exposures are typically the most productive ground.
- Mapped unit
- Hueco Formation or Group
- Age
- 300–285 Ma (Cisuralian)
- Rock types
- limestone and shale
- Elevation
- 4,650 ft
Geologic mapping via Macrostrat and the underlying state geological survey maps (CC BY 4.0). Bedrock at the surface can vary within a mapped unit.
Today's weather
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The app shows live weather, recent rain, and a daily rockhounding score for Tres Hermanas Mts.
Get the appSources & verification
Spot details combine the public RockHoundR location dataset, normalized mineral labels, agency land-status checks in the app, and community submissions. Coordinates are approximate until verified in the field.
State guidance last verified:
- Rockhound State Park, Collection rules
- BLM New Mexico
- New Mexico Bureau of Geology and Mineral Resources
- Community submissions reviewed against published agency rules
Found at Tres Hermanas Mts
Each name opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.
Dumortierite
Hydrozincite
PyrolusiteEncyclopedia →
QuartzEncyclopedia →
SmithsoniteEncyclopedia →
Willemite
Nearby rockhounding spots
Other rockhounding spots within driving distance of Tres Hermanas Mts.
- ColumbusLuna County, New Mexico · 7 mi awayOnyx
- Big Diggins MineLuna County, New Mexico · 15 mi awayAgate
- Carrizalillo Mining DistrictLuna County, New Mexico · 16 mi awayThunderegg
- Agate Point prospectLuna County, New Mexico · 18 mi awayAgate, Thunderegg
- Little Florida MountainsLuna County, New Mexico · 19 mi awayThunderegg, Agate
- Rockhound State ParkLuna County, New Mexico · 19 mi awayAgate, Blue Chalcedony, Jasper
- General Area (Luna County)Luna County, New Mexico · 28 mi awayAgate, Chalcedony, Chert
- Queen's Taste MineGrant County, New Mexico · 31 mi awayCopper
Across the state line from Tres Hermanas Mts
Tres Hermanas Mts is close enough to the New Mexico border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.
- General AreaEl Paso County, Texas · 71 mi awayGarnet, Mica, Pink Serpentine
Tres Hermanas Mts FAQ
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More rockhounding in New Mexico
See all 143 New Mexico spots →Open Tres Hermanas Mts on the map
Use the RockHoundR app for live land overlays, weather, geology, directions, and saved finds.
