Clark Valley: Apatite & Andalusite Rockhounding in Fresno County, California

Updated June 2026

Clark Valley is a mapped rockhounding spot in Fresno County, California. Reported finds include apatite, andalusite. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Fresno County
State: California
Coordinates: 36.75104, -119.37641

Geology at Clark Valley

This spot sits on gabbroic rocks, unit 2 (undivided), mapped as diorite and gabbro that formed roughly 250 to 66 million years ago. Garnet and similar hard minerals typically weather out of rock like this and concentrate as resistant grains in nearby soils and creek gravels.

Mapped unit: gabbroic rocks, unit 2 (undivided)
Age: 250–66 Ma (Triassic to Cretaceous)
Rock types: diorite and gabbro
Elevation: 920 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 Clark Valley

Best months: October to May. Typical highs run 100°F in midsummer and 59°F in midwinter, with winter lows near 36°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, FRESNO 5 NE station (18 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 California — Recreational mineral collecting
California Geological Survey
CDFW — Suction Dredge Mining Permit Program
Community submissions reviewed against published agency rules

Found at Clark 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 Clark Valley.

Clark Valley FAQ

Where is Clark Valley?+

Clark Valley is in Fresno County, California, at 36.75104, -119.37641.

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

Clark Valley is reported to produce Apatite, Andalusite.

Is collecting allowed at Clark 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 Clark Valley?+

A rock hammer, a sieve, and a small shovel work well for garnet-type minerals, which concentrate as resistant grains in soils and creek gravels.

When is the best time to visit Clark Valley?+

The most comfortable months at Clark Valley are October to May. Summer heat here is intense, so carry more water than you think you need and work the early morning.

How do I get to Clark Valley?+

Open the directions link to navigate to 36.75104, -119.37641 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in California

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Open Clark Valley on the map

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