Quartz outcrop off of jeep road: Nodules & Thundereggs Rockhounding in Maricopa County, Arizona

Quick details

Access

Public area

County

Maricopa County

State

Arizona

Nearest road

[FR 1058] **4WD**

Coordinates

33.90631, -111.76956

Geology at Quartz outcrop off of jeep road

This spot sits on granitic rocks, mapped as granite that formed roughly 1600 to 1400 million years ago. Plutonic rock like this weathers slowly into grus and boulders, and the most productive collecting is typically in weathered zones and drainages.

Mapped unit

granitic rocks

Age

1600–1400 Ma (Mesoproterozoic)

Rock types

granite

Elevation

4,050 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 Quartz outcrop off of jeep road

Best months: October to May. Typical highs run 98°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, CAREFREE station (10 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 Arizona — Recreational Mineral Collecting
• Arizona Geological Survey
• Arizona State Land Department recreation permits
• Community submissions reviewed against published agency rules

Found at Quartz outcrop off of jeep road

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

• Nodules
• ThundereggsEncyclopedia →