Sugarloaf & Ruby Mountains: Rhyolite & Perlite Rockhounding in Chaffee County, Colorado

Plan your visit

Generally open to casual rockhounding

County

Chaffee County

State

Colorado

Nearest road

CR 300

Coordinates

38.76015, -106.07219

Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.

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.

Best time to visit Sugarloaf & Ruby Mountains

Comfortable months (45 to 90°F highs)

Best months: March to November. Typical highs run 82°F in midsummer and 39°F in midwinter, with winter lows near 10°F. At about 8,310 ft, snow can block access from late fall well into spring, so check conditions outside of summer.

Climate normals: NOAA 1991-2020 monthlies, BUENA VISTA 2S station (5 mi away), adjusted for elevation.

Geology at Sugarloaf & Ruby Mountains

This spot sits on ground mapped as Topaz rhyolite flow of Nathrop Volcanics, including basal vitrophyre that formed roughly 34 to 28 million years ago. Volcanic ground like this weathers into rocky slopes and float, and fresh exposures in cuts and drainages are usually the most productive places to look.

Mapped unit

Topaz rhyolite flow of Nathrop Volcanics, including basal vitrophyre

Age

34–28 Ma (Early Oligocene)

Elevation

8,310 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.

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.

• BLM Colorado rockhounding rules
• Colorado Geological Survey
• Pike and San Isabel National Forests
• Community submissions reviewed against published agency rules