Best spot

Afton Canyon: Opalite & Jasper Rockhounding in San Bernardino County, California

Updated June 2026

Afton Canyon pairs documented BLM rockhounding access with a strong Mojave silica suite: Mindat lists opal, opalite, chalcedony, plume agate, agate-jasper, petrified wood, and jasper in the canyon area. The locality also has unusual field context because the Mojave River flows above ground here year-round, cutting through one of the region's more recognizable volcanic and sedimentary exposures. Reported finds include opalite, jasper. Below: coordinates, access notes, nearby spots, and trip-planning links.

Afton Canyon photos

Public image records connected to this spot or its reported material.

3 photos

Quick details

Access: Permission required
County: San Bernardino County
State: California
Nearest road: Mojave Road
Coordinates: 35.03910, -116.38534

Geology at Afton Canyon

This spot sits on alluvium and marine deposits, mapped as coarse alluvium that formed within roughly the last 5 million years. Gravels like these concentrate whatever survives the river: agate, jasper, and other tough silica typically show up as rounded, waxy stones.

Mapped unit: alluvium and marine deposits
Age: 5 Ma to present (Pliocene to Holocene)
Rock types: coarse alluvium
Elevation: 1,420 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 Afton Canyon

Best months: October to April. Typical highs run 108°F in midsummer and 61°F in midwinter, with winter lows near 33°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, BAKER station (24 mi away), adjusted for elevation.

Land & collecting status

Permission required before collecting

Requires landowner or agency permission before any collecting. Do not enter without explicit authorization.

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 Afton Canyon

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 Afton Canyon.

Across the state line from Afton Canyon

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

Afton Canyon FAQ

Where is Afton Canyon?+

Afton Canyon is in San Bernardino County, California, at 35.03910, -116.38534. Nearest road: Mojave Road.

What rocks and minerals can you find at Afton Canyon?+

Afton Canyon is reported to produce Opalite, Jasper.

Is collecting allowed at Afton Canyon?+

Permission required before collecting. Requires landowner or agency permission before any collecting. Do not enter without explicit authorization. Always confirm current rules with the managing agency before a trip.

What tools should I bring to Afton Canyon?+

Most agate and jasper is surface float: bring a spray bottle, a pick or small shovel, and a sturdy bag. Wet stones show their banding and translucence.

When is the best time to visit Afton Canyon?+

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

How do I get to Afton Canyon?+

Open the directions link to navigate to 35.03910, -116.38534 in Google Maps. The nearest road is Mojave Road.

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