Johnson Pass: Onyx & Calcite Rockhounding in Tooele County, Utah

Updated June 2026

Johnson Pass is a mapped rockhounding spot in Tooele County, Utah. Reported finds include onyx, calcite, galena. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Tooele County
State: Utah
Nearest road: SR 199
Coordinates: 40.33718, -112.57265

Geology at Johnson Pass

This spot sits on Chainman Shale, mapped as siltstone mudstone that formed roughly 360 to 325 million years ago. Sedimentary rock like this erodes unevenly, so the most productive collecting is typically along fresh cuts, badland slopes, and active drainages.

Mapped unit: Chainman Shale
Age: 360–325 Ma (Mississippian)
Rock types: siltstone mudstone
Elevation: 6,530 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 Johnson Pass

Best months: March to November. Typical highs run 88°F in midsummer and 35°F in midwinter, with winter lows near 15°F.

Climate normals: NOAA 1991-2020 monthlies, JOHNSON PASS station (2 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 Johnson Pass

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 Johnson Pass.

Johnson Pass FAQ

Where is Johnson Pass?+

Johnson Pass is in Tooele County, Utah, at 40.33718, -112.57265. Nearest road: SR 199.

What rocks and minerals can you find at Johnson Pass?+

Johnson Pass is reported to produce Onyx, Calcite, Galena.

Is collecting allowed at Johnson Pass?+

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 Johnson Pass?+

A rock hammer, gloves, and safety glasses cover old mining-district ground. Stay out of shafts and adits; the best specimens typically come from dump piles.

When is the best time to visit Johnson Pass?+

The most comfortable months at Johnson Pass are March to November.

How do I get to Johnson Pass?+

Open the directions link to navigate to 40.33718, -112.57265 in Google Maps. The nearest road is SR 199.

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