Red Dome’s crimson hills a cool trek southeast of Bridger

Red rock formations southeast of Bridger are part of the Chugwater Formation, where iron minerals in the soil have oxidized turning the soil and sandstone red.
Hiking among the crimson cliffs of Red Dome, located about 10 miles southeast of Bridger, seems like a trip back in time.
The red bluffs on the north and east sides of Pryor Mountain Road are checker-boarded with state and BLM lands. The hunting season provides a great time to explore the country because the private lands are included in Montana Fish, Wildlife and Parks’ Block Management Program. The program pays landowners to provide access to their private property.
A large, isolated block of sandstone weathers the wind, rain and snow on BLM land southeast of Bridger.
In FWP’s Region 5, the Block Management Area is No. 115, the JS Morgan Ranch. No motorized vehicles are allowed on the private land, so it’s walk-in only for mule deer. Upland birds are also listed as a possible species in the area.
A photo-illustrated roadside geology tour posted online by the Pryors Coalition that includes Red Dome along the route to the Pryor Mountains. According to geologist Gary Thompson the road cuts through 400 million years of geologic history. That includes Red Dome, which is part of the Triassic period Chugwater Formation, dating back 251 million years ago to when North America was still part of the huge super continent known as Pangaea.
The red sandstone comes from oxidation of iron minerals in the soil.
“One source of the iron oxide is from deeply weathered tropical soils that existed at that time,” Thompson wrote. “There are some gray streaks in these reddish rocks that are impregnated with deposits of tar. The tar is a residue of crude oil that was once trapped under an impermeable layer of gypsum in the dome.”
Portions of the Chugwater Formation can be found farther south along the Pryor Mountains near Crooked Creek, as well.
“The Chugwater Formation comprises about 500 feet of red shale, siltstone, and sandstone likely deposited in ephemeral lakes and small streams during the Early Triassic,” Thompson wrote.
If it is not hunting season, please explore this area only if you have an app or GPS that shows private land ownership to avoid trespassing. The Montana Cadastral website can also provide information on where to access the area, showing where BLM land meets the Pryor Mountain Road.
The easiest access is atop a hill about 11 miles from Bridger where there is a half section of BLM land that meets the road. Taking this route north up a valley connects to a full section of state land. This section of state land includes part of Bridger Creek and also adjoins additional portions of BLM land.
State land is accessible only to those who purchase a State Land Recreation Use Permit, which can be purchased through FWP online. The permits are $10 for adults, $5 for those age 17 and younger and seniors 60 and older. A family permit is available for $20.
5 places to explore in eastern Montana this spring
5 places to explore
One note of caution, check the weather report, because you don’t want to be driving some of eastern Montana’s back roads after it rains. The mud can be a slippery mess.
Bitter Creek Wilderness Study Area
The Bitter Creek area north of Glasgow offers a wide expanse of Bureau of Land Management and state school trust lands linked together, including the 59,000-acre Bitter Creek Wilderness Study Area. The Montana Wilderness Association is hosting a walk into the region on June 1 if you’re looking to explore with other folks. Find more info on their website. wildmontana.org
Makoshika State Park
Makoshika State Park is a good place for a day trip, or overnight stay. The badlands just outside of Glendive offer hiking, camping, a disc golf course and a great interpretive center. Buzzard Day, an annual celebration that includes races, performances and a fun run, is scheduled for June 8. stateparks.mt.gov
Medicine Rocks State Park
Travel farther sought from Glendive to Medicine Rocks State Park to explore the unique sandstone formations and check out the variety of human etchings left in the rock. Zip into nearby Ekalaka and check out the museum. stateparks.mt.gov.
Terry Badlands
Just off Interstate 94 at the town of Terry are access points to the Terry Badlands. Natural bridges, broad views of the prairie and Yellowstone River valley are highlights of this stop. The BLM land is a wilderness study area. Find more details on the agency’s website: www.blm.gov.
Ashland Ranger District
Drive south out of Miles City to reach the Ashland Ranger District, which includes rolling pine tree-covered hills in addition to a Forest Service rental cabin and an old fire lookout tower that is one of the most unusual places to watch a Shakespeare in the Parks performance. www.visitmt.com.