Yellowstone River - Black Bridge Boat Launch: Montana Moss Agate & Petrified Wood Rockhounding in Dawson County, Montana

Updated August 2026

Yellowstone River - Black Bridge Boat Launch is a mapped rockhounding spot in Dawson County, Montana. Reported finds include montana moss agate, petrified wood, jasper, chalcedony. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Dawson County
State: Montana
Nearest road: Mary Avenue
Postcode: 59330
Coordinates: 47.09995, -104.72662

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.

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.

State guidance last verified: April 1, 2026

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 Yellowstone River - Black Bridge Boat Launch

Each chip 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 Yellowstone River - Black Bridge Boat Launch.

Across the state line from Yellowstone River - Black Bridge Boat Launch

Yellowstone River - Black Bridge Boat Launch is close enough to the Montana border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Yellowstone River - Black Bridge Boat Launch FAQ

Where is Yellowstone River - Black Bridge Boat Launch?+

Yellowstone River - Black Bridge Boat Launch is in Dawson County, Montana, at 47.09995, -104.72662. Nearest road: Mary Avenue.

What rocks and minerals can you find at Yellowstone River - Black Bridge Boat Launch?+

Yellowstone River - Black Bridge Boat Launch is reported to produce Montana Moss Agate, Petrified Wood, Jasper, Chalcedony.

Is collecting allowed at Yellowstone River - Black Bridge Boat Launch?+

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. Always confirm current rules with the managing agency before a trip.

What tools should I bring to Yellowstone River - Black Bridge Boat Launch?+

A rock hammer, sturdy gloves, and a padded bag cover petrified wood hunting. Most pieces are surface float, so walking slopes and washes beats digging.

How do I get to Yellowstone River - Black Bridge Boat Launch?+

Open the directions link to navigate to 47.09995, -104.72662 in Google Maps. The nearest road is Mary Avenue.

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Open Yellowstone River - Black Bridge Boat Launch on the map

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