Warsaw: Agate & Chert Rockhounding in Benton County, Missouri

Plan your visit

Generally open to casual rockhounding

County

Benton County

State

Missouri

Coordinates

38.18676, -93.38206

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 Harry S. Truman Reservoir is U.S. Army Corps of Engineers land, and roughly 100,000 acres of public land and shoreline surround the lake; surface mineral pickup on exposed shoreline gravel is generally low-impact, but Corps rules vary by tract, so confirm with the Kansas City District before digging. Mozarkite also turns up in public road ditches and creek gravels near Warsaw. Avoid Missouri Department of Conservation tracts (collecting prohibited) and private land.

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 Warsaw

Comfortable months (45 to 90°F highs)

Best months: February to December. Typical highs run 89°F in midsummer and 42°F in midwinter, with winter lows near 22°F.

Climate normals: NOAA 1991-2020 monthlies, TRUMAN DAM & RSVR station (5 mi away).

Geology at Warsaw

This spot sits on ground mapped as limestone and siltstone that formed roughly 360 to 325 million years ago. Chert and agate nodules typically form inside carbonate rock like this and weather out as tough, waxy lumps in soils and creek beds.

Age

360–325 Ma (Mississippian)

Rock types

limestone and siltstone

Elevation

840 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.

• Missouri Geological Survey
• Mark Twain National Forest
• Missouri State Parks rules
• Community submissions reviewed against published agency rules