Amasa Valley: Albite & Biotite Rockhounding in Millard County, Utah

Updated June 2026

Amasa Valley is a mapped rockhounding spot in Millard County, Utah. Reported finds include albite, biotite, diopside, garnet, gold, and more. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Millard County
State: Utah
Coordinates: 39.18447, -113.37284

Geology at Amasa Valley

This spot sits on ground mapped as Big Horse Limestone Member of the Orr Formation that formed roughly 540 to 485 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: Big Horse Limestone Member of the Orr Formation
Age: 540–485 Ma (Cambrian)
Elevation: 7,940 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.

Best time to visit Amasa Valley

Best months: March to October. Typical highs run 83°F in midsummer and 31°F in midwinter, with winter lows near 5°F. At about 7,940 ft, snow can block access from late fall well into spring, so check conditions outside of summer.

Climate normals: NOAA 1991-2020 monthlies, ESKDALE station (32 mi away), adjusted for elevation.

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.

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.

Sources & 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: April 1, 2026

BLM Utah — Rockhounding overview
Utah Geological Survey — collecting guidelines
SITLA — surface use rules
Community submissions reviewed against published agency rules

Found at Amasa Valley

Each chip opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.

Nearby rockhounding spots

Other rockhounding spots within driving distance of Amasa Valley.

Across the state line from Amasa Valley

Amasa Valley is close enough to the Utah border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Snake RangeWhite Pine County, Nevada · 38 mi awaySilver, Tungsten

Amasa Valley FAQ

Where is Amasa Valley?+

Amasa Valley is in Millard County, Utah, at 39.18447, -113.37284.

What rocks and minerals can you find at Amasa Valley?+

Amasa Valley is reported to produce Albite, Biotite, Diopside, Garnet, Gold, Idocrase, Molybdenite, Pyrite, Scheelite, Tourmaline, Tremolite, Wollastonite.

Is collecting allowed at Amasa Valley?+

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. Always confirm current rules with the managing agency before a trip.

What tools should I bring to Amasa Valley?+

A gold pan, a classifier screen, a small shovel, and a snuffer bottle cover the basics. Motorized equipment and sluices fall under separate rules in most states, so start with hand tools.

When is the best time to visit Amasa Valley?+

The most comfortable months at Amasa Valley are March to October. At about 7,940 ft, snow can block access from late fall well into spring, so check conditions outside of summer.

How do I get to Amasa Valley?+

Open the directions link to navigate to 39.18447, -113.37284 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in Utah

See all 246 Utah spots →

Open Amasa Valley on the map

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