Pompeys Pillar National Monument is a massive sandstone outcrop that rises from an almost two acre base on the banks of the Yellowstone River 150 feet toward Montana’s Big Sky, east of Billings. The monument’s premier location at a natural ford in the Yellowstone River and its geologic distinction as the only major sandstone formation in the area, have made Pompeys Pillar a celebrated landmark and outstanding observation point for more than eleven thousand years of human occupation. Hundreds of markings, petroglyphs and inscriptions left by visitors have transformed this geologic phenomenon into a living journal of the American West. Pompeys Pillar was designated as a National Monument in January 2001. Prior to its monument status, it was a designated National Historic Landmark in 1965.
In his journals, Clark named the Pillar “Pomp’s Tower.” Pomp was Clark’s nickname for young Baptiste Charbonneau, infant son of Sacagawea, the Shoshoni woman who accompanied the expedition and contributed greatly to its success. An image of Sacagawea carrying young Pompy adorns the new United States golden dollar coin. Pompy means little chief in the Shoshoni language. The name was changed to Pompeys Pillar when an account of the Expedition was published by Nicolas Biddle in 1814.
History & Culture
Archaeological evidence of past occupation of the Pompeys Pillar National Monument area by Native Americans has been discovered at various depths below ground. These materials appear to be the remains of hunting and living camps, probably occupied by relatively small groups of people for short periods of time. The remains of butchered bison and other animals along with mussels from the nearby Yellowstone River are scattered among flaked stone tools and debris around small surface hearths. The ancient camps were buried by slow-moving flood waters soon after abandonment, preserving organic and other materials in place, with later occupations leaving remains on the new, higher surfaces. Archaeological investigations in the Yellowstone Valley floor itself have been rare in the past because most of the land here is private. Equally important is the complementary information recently gathered on the past environments of the Pompeys Pillar area. Paleoenvironmental studies are an essential part of archaeological research, but very little of this work has been done on the Yellowstone.
The Yellowstone River has long been of significance to the Crow people. Clark made several entries in his journals seeing “signs” of the Crow, but never actually encountered them. On July 18, 1806, he noted seeing the “Smoke” of the Crow Indians. On July 19th, the Clark party passed an “old indian fort on an island,” and one expedition member, George Shannon, reported that there was a “remarkable Lodge” downstream near the mouth of the Clarks Fork of the Yellowstone River (now owned by BLM). The Yellowstone Valley has long been the heart of Crow Country and is steeped in Crow history.
Pompeys Pillar National Monument’s most notable visitor, Captain William Clark of the Lewis and Clark Expedition, arrived at Pompeys Pillar on July 25, 1806, on his return trip from the Pacific coast. Clark’s journal recorded his stop at this “remarkable rock” with its “extensive view in every direction.” He described an idyllic landscape of grassy plains, snow-capped mountains and cliffs abutting the wandering river. Clark marked his presence by engraving his name and the date of his visit on the outcrop. This simple inscription is the only remaining physical evidence of Lewis and Clark’s epic journey.
In his journal, Clark named the rock Pompy’s Tower, Pompy being Clark’s nickname for Sacagawea’s young son, Jean Baptiste Charbonneau, who was born at the expedition’s winter camp at Fort Mandan on February 11, 1805. The name was changed to Pompeys Pillar by author Nicholas Biddle when his account of the Expedition was published in 1814. Ethnographic and archaeological evidence indicates that the Pillar was a place of ritual and religious activity.
Hundreds of petroglyphs on the face of the rock, noted by Clark in his journal, reflect the importance of the monument to early peoples. The Crow people, the dominant residents of the region when Clark passed through, call the pillar the “Mountain Lions Lodge” in their language and it figures prominently in Crow oral history.
Pompeys Pillar also includes the markings and signature of a host of characters from the pioneer past, including fur trappers, Yellowstone River steamboat men, frontier army troops, railroad workers, missionaries and early settlers. In 1873, Lieutenant Colonel George Armstrong Custer and his men camped at its base, where they came under attack from Sioux snipers.
Nature & Science
Geology
Visitors see the geologic roots of Pompeys Pillar National Monument in the Hell Creek formation exposed by the unbridled Yellowstone River as it winds through bottom lands filled with towering cottonwood trees on one bank and the sandstone cliffs dotted with pine and sagebrush on the other. Pompeys Pillar and the cliffs along the north bank of the river across from the Pillar are composed of sandstones and shales of the Upper Cretaceous Hell Creek (Lance) Formation. The Hell Creek Formation, ranging from 75-65 million years ago, represents the last strata of the Cretaceous Period. The Hell Creek Formation has been found to contain the fossilized remains of dinosaurs and primitive mammals.
Ecology
The Pompeys Pillar National Monument area is more than a static piece of history or a crossroads for bygone cultures. It is alive with wildlife. Clark noted seeing wildlife in abundance here and elsewhere along the Yellowstone. And Pompeys Pillar is still home to many wildlife species and serves area communities as a viewing area. More than 100 different bird species have been counted in the area including owls, sandpipers, terns and bald eagles. Deer, fox, coyotes, raccoons and numerous small mammals, amphibians and reptiles call the Pillar home. Much of the wildlife population is a result of the site’s thriving riparian zone, a healthy plant community of grasses, willows and cottonwood trees that stabilize the river bank and provide important habitat.
Today’s existing ecosystem at the Pompeys Pillar National Monument is typical of the Yellowstone Valley as Clark would have seen it in 1806. Some of the upland junipers growing around the pillar itself were here hundreds of years before Clark made his historic stop.
Attractions
Boardwalk
A boardwalk leads from the visitor station up the Pillar to Clark’s signature and continues to the top of mesa. It is approximately 1,000 feet long and contains about 200 steps.
Day Use Area
The day use area is ideal for picnicking or relaxing. It is adjacent to the Yellowstone River and shaded by large cottonwood trees.
Getting There
By Car
Pompeys Pillar National Monument is easily accessible from Interstate 94, using exit 23, or from State Highway 312. The Pillar is a sandstone butte or mesa covering about 2 acres at its base and standing about 150 feet high. Because it is the only sandstone outcrop on the south side of the Yellowstone River for several miles in either direction, it has been a landmark for centuries.
Traveler Facts
Contact Information
Pompeys Pillar National Monument
BLM Billings Field Office
5001 Southgate Drive
Billings, MT 59101
Phone: 406-896-5013
Phone: 406-875-2233 (Visitor Information)
Operating Hours & Seasons
From Memorial Day weekend through Labor Day, the National Monument is open to drive-in visitation from 8:00 a.m. to 8 pm. after Labor Day through the remainder of September the hours are 9:00 a.m. to 5:00 p.m. From October to the Memorial Day weekend, vehicle gates are closed, but the Monument is open to walk-in visitors although no services are available. The walk from the gates to the Pillar is about 3/4 mile. Special arrangements can be made during the off-season for school programs and other special events.
