Mushroom Rocks: Pyrite Concretions Rockhounding in Ellsworth County, Kansas

Quick details

Access

Permission required

County

Ellsworth County

State

Kansas

Nearest road

Avenue K

Coordinates

38.72625, -98.03040

Geology at Mushroom Rocks

This spot sits on Dakota Formation, mapped as claystone, mudstone, and shale that formed roughly 145 to 100 million years ago. Sedimentary rock like this erodes unevenly, so the most productive collecting is typically along fresh cuts, badland slopes, and active drainages.

Mapped unit

Dakota Formation

Age

145–100 Ma (Early Cretaceous)

Rock types

claystone, mudstone, and shale

Elevation

1,560 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 Mushroom Rocks

Best months: February to June. Typical highs run 92°F in midsummer and 41°F in midwinter, with winter lows near 19°F.

Climate normals: NOAA 1991-2020 monthlies, KANOPOLIS LAKE station (9 mi away).

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.

Sources: RockHoundR public spot dataset, app land overlays, and local agency review before each trip.

Found at Mushroom Rocks

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

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