Geology
Minerals, geology & paleontology on the Beaverhead-Deerlodge National Forest
Many of the famous mining discoveries that drove early pioneers west are found on or near the Beaverhead-Deerlodge National Forest. While the history of the region is strongly associated mining, it’s only one facet of our minerals and geology program. We also perform research and manage paleontological resources (fossils), mineral materials (landscape rock, gravel), leasable and salable resources, and abandoned mine lands.
Geologic history
The geologic history of the Beaverhead-Deerlodge National Forest is both rich and ancient. With rocks over three billion years old and evidence of tropic inland oceans from 1.5 billion years ago, the landscape tells the story of our planet’s early stages and constant changes.
About 180 million years ago, geologic events that would shape nineteenth century westward expansion took place. Volcanoes formed when the Pacific Ocean floor moved under the North American continent and spewed magma, which eventually created metals like copper, silver, and gold.
Relatively recently—a mere 17 million years ago—many of the mountain ranges we see today were formed by tectonic plate extension. They were further sculpted by glacial ice 12,000 years ago, giving them their distinct jagged peaks and alpine lakes.
Locatables
Locatables in Montana are strongly associated with mining and the early gold rushes that brought people to the region in the nineteenth century. The Forest Service defines locatables in FSM 2811.2 as “hard rock minerals which are mined and processed for the recovery of metals. They also may include certain nonmetallic minerals and uncommon varieties of mineral materials, such as valuable distinctive deposits of limestone or silica.”
Types of mining claims
Before you engage in any type of mining activity, please contact the appropriate Ranger District for guidance on permitting and rules. There are four types of mining claims on the Beaverhead-Deerlodge National Forest.
Lode claims
A mining claim on public lands with a defined vein, lode, or other rock bearing metallic or other valuable deposits. Lode claims may not exceed 1500’ in length and may not be more than 300’ on each side of the middle of the vein at surface.
Placer claims
A claim for valuable minerals that occur outside of a vein or lode, such as gold contained in gravel and deposits or uncommon varieties of mineral materials.
Millsite claims
A type of claim used only for mining or milling purposes that may not exceed five acres and must be described by meters-and-bounds or by legal subdivisions.
Tunnel site claims
Tunnel site claimants acquire 3,000’ from the face of the tunnel in a straight line, limited to the width of the tunnel. The person acquiring the claim attains the right of all veins or lodes not previously known to exist and discovered in the tunnel. After discovery, the owner may locate a lode claim on the surface extending 1,500’ along the lode.
Mineral materials
Outside of the traditional rockhounding, many people wish to take rock from Forest lands to create a firepit in their backyard, line their garden, or a walkway. The Forest Service offers free mineral material permits for personal use. These are issued on a case-by-case basis. Please contact your local Ranger District office for more information.
Abandoned mines
Visitors check out an abandoned mine in Coolidge ghost town off of the Pioneer Scenic Byway.
Due to the extensive mining history across the Forest, there’s a good chance you’ll encounter old mine workings when you’re out on the landscape. Please exercise extreme caution if you find an old mine. Whether they’re pits, trenches, adits, or shafts, we embrace the motto of “stay out, stay alive.”
If open adits or shafts are found, we urge you to keep a safe distance, refrain from entering, and contact your local Ranger District. The minerals and geology program completes reclamation work on abandoned mines to keep the public safe by backfilling pits or trenches and installing bat-friendly gates on shafts or adits or backfilling them if conditions permit.
Paleontology
Due to its rich geologic history, the forest hosts a plethora of geologic phenomena, including fossils. Whether it’s an impression of a plant leaf or the fossilized remains of a mammal, these artifacts stir imagination and provide a glimpse into what the landscape used to look like with its diverse flora and fauna.
Due to their scientific importance, the collection of any vertebrate fossil is strictly prohibited on National Forest lands. If you believe you have found fossilized remains, we encourage you to get a location and report it to the local Ranger District for further examination.
While it’s tempting to post locations of your find online, we ask that you refrain from this as it often leads to damage or destruction of the resource. The Forest Service issues paleontology permits to universities for study as well as museum curation of finds. Locally, the Museum of the Rockies in Bozeman, MT, houses specimens that have been found on the Forest.
Discovering dinosaurs
In 2007, a new species of dinosaur was discovered on the forest, called Oryctodromeus cubicularis. The remains of an adult and two juveniles were found in the chamber of a filled burrow. A small (approximately 6.8 feet long, weighing 70 pounds) ornithopod dinosaur that borrowed in dens, Oryctodromeus cubicularis was preserved in 95-million-year-old rocks.