Morgan Hill Creeks: Poppy Jasper Rockhounding in Santa Clara County, California

Quick details

Access

Public area

County

Santa Clara County

State

California

Nearest road

Watsonville Road

Postcode

95046

Coordinates

37.05509, -121.66364

Geology at Morgan Hill Creeks

This spot sits on ground mapped as Older alluvial fan deposits that formed within roughly the last 12,000 years. Gravels like these concentrate whatever survives the river: agate, jasper, and other tough silica typically show up as rounded, waxy stones.

Mapped unit

Older alluvial fan deposits

Age

< 1 Ma (Holocene)

Elevation

360 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 Morgan Hill Creeks

Conditions here are workable year-round, with typical highs from 60°F in winter to 87°F in summer.

Climate normals: NOAA 1991-2020 monthlies, GILROY station (7 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 California — Recreational mineral collecting
• California Geological Survey
• CDFW — Suction Dredge Mining Permit Program
• Community submissions reviewed against published agency rules

Found at Morgan Hill Creeks

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

• Poppy JasperEncyclopedia →