Lake Mountain: Endellite & Halloysite Rockhounding in Utah County, Utah

Quick details

Access

Permission required

County

Utah County

State

Utah

Coordinates

40.20688, -111.93828

Geology at Lake Mountain

This spot sits on ground mapped as Oquirrh Group, Butterfield Peaks Formation that formed roughly 325 to 305 million years ago. Fresh exposures, cuts, and drainages are typically the most productive places to look on ground like this.

Mapped unit

Oquirrh Group, Butterfield Peaks Formation

Age

325–305 Ma (Pennsylvanian)

Elevation

6,240 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 Lake Mountain

Best months: March to November. Typical highs run 85°F in midsummer and 34°F in midwinter, with winter lows near 8°F.

Climate normals: NOAA 1991-2020 monthlies, FAIRFIELD station (9 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 Utah — Rockhounding overview
• Utah Geological Survey — collecting guidelines
• SITLA — surface use rules
• Community submissions reviewed against published agency rules

Found at Lake Mountain

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

• Endellite
• Halloysite
• Olivine