Pompeys Pillar National Monument overlooks the Yellowstone River about 25 miles east of Billings, in south central Montana.
At only 51 acres, it is one of the smallest National Monuments in the National Parks system.
The new Pompeys Pillar Interpretive Center opened in 2006. Exhibits in the 5,700-square foot center relate the journey of Captain William Clark and his detachment, including Sacagawea and her son Pomp, down the Yellowstone River Valley in 1806.
From June 30 to July 3, 1806, Lewis and Clark decided that it would be best to divide the group into separate parties, maximizing their ability to explore the vast area.
Clark and his party traversed Bozeman Pass, set out down the Yellowstone River, and headed for the caches at Beaverhead.
Along the way, the crew came across a prominent rock formation, located on the south bank of the river in present-day Nibbe, Montana. He named the natural formation after Sacagawea's child Jean Baptiste Charbonneau, or "Pomp".
|Pompeys Pillar Interpretive Center
Clark left his mark at Pompeys Pillar, engraving his name and the date, July 25, 1806, into the stone. His signature is still visible today, the only remaining physical evidence found along the route that was followed by the expedition.
The pillar itself stands 150 feet above the Yellowstone River and consists of sandstone from the late Cretaceous Hell Creek Formation.
It is managed by the Bureau of Land Management, U.S. Department of the Interior. The Pillar is open to walk-in and drive-in visitation. The base of the pillar is approximately 1 acre. Visitors can climb to the top of the pillar via a series of steep wooden steps.
The area is easily accessible from Interstate 94, using exit 23, or from Montana Highway 312.
We have visited Pompeys Pillar on our journeys to Montana, and enjoyed learning more about the Lewis and Clark Expedition, and loved the opportunity to see and hear the Yellowstone River up close and personal!
|Sign at Pompeys Pillar Interpretive Center
| Pompeys Pillar National Monument
3039 U.S. Highway 312
Pompeys Pillar, MT 59064
Website of Pompeys Pillar National Monument
|Pompeys Pillar, with the steps ascending to the peak
|View from the top of Pompeys Pillar, with the Yellowstone River in the distance