Bells Mill Park: Calcite Rockhounding in Hamilton County, Iowa
- Mineral reported
- 1
- Elevation
- 950 ft
- Best months
- March to November
Bells Mill Park preserves outcrops along the Boone River where dark, well-formed calcite crystals occur in the Mississippian carbonates, an unusual and distinctive Iowa mineral locality. Unlike the state's ubiquitous glacial agate, this is a bedrock mineral occurrence tied to one specific valley. The park's river frontage keeps loose material replenished in the Boone River gravels. Reported finds include calcite. Below: coordinates, access notes, nearby spots, and trip-planning links.
Plan your visit
Generally open to casual rockhounding
- County
- Hamilton County
- State
- Iowa
- Nearest road
- Bell's Mill Road
- Postcode
- 50249
- Coordinates
- 42.34056, -93.89169
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: Bells Mill Park is a Hamilton County Conservation park, not a state park, and is open to the public. Confirm the county board's collecting policy, and keep to loose material along the Boone River gravel below the ordinary high-water mark rather than breaking outcrops.
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 Bells Mill Park
Comfortable months (45 to 90°F highs)
Best months: March to November. Typical highs run 83°F in midsummer and 27°F in midwinter, with winter lows near 7°F.
Climate normals: NOAA 1991-2020 monthlies, WEBSTER CITY station (10 mi away).
Geology at Bells Mill Park
This spot sits on ground mapped as lower Cherokee Group that formed roughly 325 to 305 million years ago. Fresh exposures, cuts, and drainages are typically the most productive places to look on ground like this.
- Mapped unit
- lower Cherokee Group
- Age
- 325–305 Ma (Pennsylvanian)
- Elevation
- 950 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.
Today's weather
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The app shows live weather, recent rain, and a daily rockhounding score for Bells Mill Park.
Get the appSources & 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.
- Iowa Geological Survey
- Iowa DNR state park rules
- Community submissions reviewed against published agency rules
Found at Bells Mill Park
Each name 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 Bells Mill Park.
- Fort DodgeWebster County, Iowa · 16 mi awayGypsum
- AmesStory County, Iowa · 25 mi awayChalcedony, Fossil
- NevadaStory County, Iowa · 35 mi awayAgate
- EldoraHardin County, Iowa · 40 mi awayGeode
- Steamboat RiverHardin County, Iowa · 42 mi awayGeode
- UnionHardin County, Iowa · 43 mi awayGeode
- ChapinFranklin County, Iowa · 49 mi awayGeode
- SheffieldCerro Gordo County, Iowa · 54 mi awayGeode
Bells Mill Park FAQ
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