Arthur's Fork: Biotite & Monazite Rockhounding in Morgan County, Utah

Updated June 2026

Arthur's Fork is a mapped rockhounding spot in Morgan County, Utah. Reported finds include biotite, monazite, molybdenite, uraninite, xenotime. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Morgan County
State: Utah
Coordinates: 40.93473, -111.75093

Geology at Arthur's Fork

This spot sits on ground mapped as Tintic Quartzite that formed roughly 540 to 495 million years ago. Metamorphic rock like this weathers into resistant float, and minerals that survive transport typically concentrate in nearby drainages.

Mapped unit: Tintic Quartzite
Age: 540–495 Ma (Early Cambrian to Middle Cambrian)
Elevation: 6,030 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 Arthur's Fork

Best months: March to October. Typical highs run 83°F in midsummer and 32°F in midwinter, with winter lows near 19°F.

Climate normals: NOAA 1991-2020 monthlies, BOUNTIFUL BENCH station (6 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 Arthur's Fork

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 Arthur's Fork.

Across the state line from Arthur's Fork

Arthur's Fork 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.

Fort BridgerUinta County, Wyoming · 77 mi awayAgate, Jasper, Silicified Agate

Arthur's Fork FAQ

Where is Arthur's Fork?+

Arthur's Fork is in Morgan County, Utah, at 40.93473, -111.75093.

What rocks and minerals can you find at Arthur's Fork?+

Arthur's Fork is reported to produce Biotite, Monazite, Molybdenite, Uraninite, Xenotime.

Is collecting allowed at Arthur's Fork?+

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 Arthur's Fork?+

A rock hammer, sturdy gloves, safety glasses, and a collecting bag cover the basics here. Add a spray bottle: wet rock shows color and pattern that dry rock hides.

When is the best time to visit Arthur's Fork?+

The most comfortable months at Arthur's Fork are March to October.

How do I get to Arthur's Fork?+

Open the directions link to navigate to 40.93473, -111.75093 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in Utah

See all 246 Utah spots →

Open Arthur's Fork on the map

Use the RockHoundR app for live land overlays, weather, geology, directions, and saved finds.