Neptune State Park (Gwynn Creek): Agate & Jasper Rockhounding in Lane County, Oregon

Updated August 2026

Neptune State Park (Gwynn Creek) is a mapped rockhounding spot in Lane County, Oregon. Reported finds include agate, jasper, petrified wood. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Lane County
State: Oregon
Nearest road: Oregon Coast Highway
Postcode: 97498
Coordinates: 44.26984, -124.10824

Geology at Neptune State Park (Gwynn Creek)

This spot sits on surficial deposits; Coastal terrace deposits, mapped as marine sand, fossils: wood fossils, and sand that formed within roughly the last 3 million years. Petrified wood typically travels as tough float, and worked gravels like these are exactly where weathered pieces tend to collect.

Mapped unit: surficial deposits; Coastal terrace deposits
Age: 3 Ma to present (Quaternary)
Rock types: marine sand, fossils: wood fossils, and sand
Elevation: 30 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 Neptune State Park (Gwynn Creek)

Conditions here are workable year-round, with typical highs from 53°F in winter to 64°F in summer.

Climate normals: NOAA 1991-2020 monthlies, YACHATS station (4 mi away).

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 Oregon/Washington — Rockhounding & mineral material
Oregon Department of Geology and Mineral Industries (DOGAMI)
Oregon Parks and Recreation Department — beach collecting rules
Community submissions reviewed against published agency rules

Found at Neptune State Park (Gwynn Creek)

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 Neptune State Park (Gwynn Creek).

Neptune State Park (Gwynn Creek) FAQ

Where is Neptune State Park (Gwynn Creek)?+

Neptune State Park (Gwynn Creek) is in Lane County, Oregon, at 44.26984, -124.10824. Nearest road: Oregon Coast Highway.

What rocks and minerals can you find at Neptune State Park (Gwynn Creek)?+

Neptune State Park (Gwynn Creek) is reported to produce Agate, Jasper, Petrified Wood.

Is collecting allowed at Neptune State Park (Gwynn Creek)?+

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 Neptune State Park (Gwynn Creek)?+

A rock hammer, sturdy gloves, and a padded bag cover petrified wood hunting. Most pieces are surface float, so walking slopes and washes beats digging.

When is the best time to visit Neptune State Park (Gwynn Creek)?+

Neptune State Park (Gwynn Creek) is workable year-round.

How do I get to Neptune State Park (Gwynn Creek)?+

Open the directions link to navigate to 44.26984, -124.10824 in Google Maps. The nearest road is Oregon Coast Highway.

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Open Neptune State Park (Gwynn Creek) on the map

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