Pompeys Pillar National Monument
3039 US-312
Pompeys Pillar, MT
A lone sandstone butte on the Yellowstone where William Clark carved his name in 1806, the only mark the Corps of Discovery left that you can still touch.
Pompeys Pillar is a lone sandstone butte on the bank of the Yellowstone River, about twenty-five miles east of Billings, rising some one hundred fifty feet above the plain. On its face is the signature of Captain William Clark, carved on July 25, 1806, as he returned east down the Yellowstone during the Lewis and Clark Expedition. It is the only piece of physical evidence from the entire Corps of Discovery that remains visible on the ground.
Clark named the rock for Pomp, the nickname of Jean Baptiste Charbonneau, the young son of Sacagawea who traveled with the expedition. But the butte was a landmark long before Clark arrived. For thousands of years, Native peoples, including the Apsaalooke, or Crow, used it as a marker along their routes, leaving petroglyphs and inscriptions that share the same stone.
What Guests Love
- Seeing William Clark's actual 1806 signature carved in the sandstone, under protective glass
- Climbing the boardwalk stairs to the top for a sweeping view of the Yellowstone valley
- Older Native petroglyphs and inscriptions layered across the same rock
- A well-told visitor center that sets the butte in the whole sweep of the Corps of Discovery
Worth Knowing
- The monument is seasonal, generally open through the warmer months, so check before a shoulder-season trip
- It is a short but stair-heavy climb to the top on a boardwalk
- The signature is protected behind glass; this is a look-only place, so do not add your own mark
- Summer heat on the open butte can be intense, so bring water and sun protection
Details
Pompeys Pillar, MT
Learn about Pompeys Pillar National Monument
Clark's mark on the Yellowstone
On the expedition's return journey in 1806, the party split, and Clark led a group down the Yellowstone River. On July 25 he stopped at the butte, climbed it, and carved his name and the date into the soft sandstone, then noted the landmark in his journal. That inscription survived the centuries where the expedition's forts, caches, and camps did not, making it the one spot where you can stand exactly where a member of the Corps stood and see proof he was there.
Clark named the rock Pompy's Tower, after Pomp, the nickname he had given Jean Baptiste Charbonneau, Sacagawea's little boy. A later editor changed it to Pompeys Pillar, and the name stuck. The signature is now protected behind glass, and it was recognized when the site was named a National Historic Landmark in 1965 and a National Monument in 2001.
A landmark long before 1806
For thousands of years before Clark, Native peoples used this butte as a landmark for travel, hunting, and ceremony. It stood out on the open river plain, a natural waypoint on routes across the Yellowstone country, and the Apsaalooke, or Crow, whose homeland this is, knew it well and hold it in regard today.
The rock carries hundreds of markings beyond Clark's, including petroglyphs and pictographs left by those earlier peoples. Reading the butte, you can see it as a kind of guestbook of the plains, signed across many centuries by many hands.
The view from the top
A boardwalk and stairs climb the butte to a viewing platform at the summit. From the top, the Yellowstone River curls below through its cottonwood bottoms, and the high plains spread out toward distant ranges. It is easy to understand why a landmark this isolated drew travelers of every era.
The river bottom is good wildlife habitat, with deer, beaver, and a steady traffic of birds along the water, while raptors ride the thermals above the open butte. In summer the sandstone bakes and the cottonwoods offer welcome shade near the base.
Closest Boutels
The closest Boutel™ stays, so you can turn this stop into an overnight. Each is an independently owned, editorially selected place to stay.
Things to Do Near Pompeys Pillar
Pictograph Cave State Park
About 30 miles west
Three sandstone shelters near Billings painted with figures up to two thousand years old, and the site of Montana's first great archaeological dig.
Billings
About 25 miles west
Montana's largest city, with the Yellowstone Art Museum, the sandstone rimrocks, and Moss Mansion.
Little Bighorn Battlefield National Monument
About 60 miles southeast
The 1876 battlefield where the Lakota, Cheyenne, and Arapaho defeated Custer's Seventh Cavalry, now told from all sides.