Terry: Petrified Wood & Chalcedony Rockhounding in Prairie County, Montana
- Minerals reported
- 3
- Elevation
- 2,370 ft
- Best months
- March to October
Terry is a mapped rockhounding spot in Prairie County, Montana. Reported finds include petrified wood, chalcedony, jasper. Below: coordinates, access notes, nearby spots, and trip-planning links.
Plan your visit
Generally open to casual rockhounding
- County
- Prairie County
- State
- Montana
- Nearest road
- Broadview Bench Road
- Coordinates
- 46.77271, -105.25989
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.
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 Terry
Comfortable months (45 to 90°F highs)
Best months: March to October. Typical highs run 88°F in midsummer and 28°F in midwinter, with winter lows near 6°F.
Climate normals: NOAA 1991-2020 monthlies, TERRY station (2 mi away).
Geology at Terry
This spot sits on Lebo Member of Fort Union Formation, mapped as shale, sandstone, and bentonite that formed roughly 66 to 62 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
- Lebo Member of Fort Union Formation
- Age
- 66–62 Ma (Paleocene)
- Rock types
- shale, sandstone, and bentonite
- Elevation
- 2,370 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 Terry.
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.
State guidance last verified:
- BLM Montana, Recreational mineral collecting
- Montana Bureau of Mines and Geology
- Gem Mountain Sapphire Mine (fee-dig operator)
- Community submissions reviewed against published agency rules
Found at Terry
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 Terry.
- FallonPrairie County, Montana · 10 mi awayMontana Agate
- Hatchet CreekPrairie County, Montana · 11 mi awayMontana Agate
- Cracker Box CreekDawson County, Montana · 19 mi awayMontana Agate
- Sand CreekDawson County, Montana · 23 mi awayMontana Agate
- Yellowstone River - Black Bridge Boat LaunchDawson County, Montana · 34 mi awayMontana Moss Agate, Petrified Wood, Jasper
- GlendiveDawson County, Montana · 37 mi awayAgate, Jasper, Moss Opal
- Custer CountyCuster County, Montana · 40 mi awayMontana Agate
- Yellowstone River - Rosebud AccessRosebud County, Montana · 67 mi awayMontana Moss Agate, Petrified Wood, Jasper
Terry FAQ
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More rockhounding in Montana
See all 106 Montana spots →Open Terry on the map
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