Platte River: Agate & Chalcedony Rockhounding in Buffalo County, Nebraska

Plan your visit

Generally open to casual rockhounding

County

Buffalo County

State

Nebraska

Nearest road

Huron Drive

Postcode

68849

Coordinates

40.66114, -99.07084

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.

Access note: The Platte is legally non-navigable in Nebraska, so the bed and bars are owned by the adjacent landowners, not open by default. Collect only from public accesses, bridge right-of-ways, and public land along the river, and get permission before crossing private ground. State recreation areas (for example Fort Kearny SRA) prohibit rock collecting under Nebraska Game and Parks rules.

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 Platte River

Comfortable months (45 to 90°F highs)

Best months: March to November. Typical highs run 87°F in midsummer and 36°F in midwinter, with winter lows near 14°F.

Climate normals: NOAA 1991-2020 monthlies, KEARNEY 4 NE station (5 mi away).

Geology at Platte River

This spot sits on Ogallala Group or Formation, mapped as siltstone mudstone and conglomerate sandstone that formed roughly 23 to 5 million years ago. Sedimentary beds like these are the typical host for petrified and silicified wood, which weathers out as durable float on slopes and in washes.

Mapped unit

Ogallala Group or Formation

Age

23–5 Ma (Miocene)

Rock types

siltstone mudstone and conglomerate sandstone

Elevation

2,140 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.

• Nebraska National Forests and Grasslands
• Conservation and Survey Division, University of Nebraska
• Nebraska Game and Parks rules
• Community submissions reviewed against published agency rules