Loaded with Horseshoes:

The Strange Career of the Bighorn Gun

In the summer of 1875, a small band of Bozeman traders dragged an aging piece of field artillery down the Yellowstone River and planted it inside a hastily built stockade near the mouth of the Bighorn. The post did not last a year. The gun, however, outlived it by generations. Yet in the collective memory of the men who served alongside it, this single weapon achieved a status few other artifacts of the Montana frontier ever matched. Contemporaries called it, without apparent irony, an object the mountaineers “nearly idolize” (Leeson). Its story is a compact window into the volatile years just before the Great Sioux War, when private commerce, tribal sovereignty, and military improvisation collided along one of the last unceded stretches of the northern plains.

A Gun Forged on the Bozeman Trail

The piece of ordnance that came to be known as the Bighorn gun did not begin its career at the river that gave it a name. According to the nineteenth-century regional history compiled by Michael A. Leeson, the gun had already seen hard use by 1870, when it accompanied a march from the North Platte River to Bozeman—one of many armed escorts that shepherded travelers and freight along the corridor blazed a few years earlier by John Bozeman and John Jacobs (Leeson; Buckley). That corridor, threading northwest from the North Platte through Powder River country and past the Bighorn Mountains, had been a flashpoint since 1866, when the army built Forts Reno, Phil Kearny, and C. F. Smith to protect it, and the Lakota, Cheyenne, and Arapaho fought two years of running war to close it (Buckley). The Fort Laramie Treaty of 1868 forced the army to abandon those posts and cede the road, but the treaty did nothing to stop civilian traffic, and armed parties like the one the gun traveled with in 1870 continued to move through contested ground.

By 1873 the same weapon, or one carrying its reputation, had been attached to a civilian expedition of roughly a hundred and forty-nine men under a Colonel Brown, ostensibly organized to prospect for minerals but evidently prepared to fight (Leeson). The party pushed down the Yellowstone as far as the Bighorn, skirmished with Sioux warriors, then cut overland to the Rosebud, where it reportedly withstood days of sustained combat before turning back along the Bozeman road. Correspondence from the period, quoted secondhand in Leeson’s history, described the results in florid terms, crediting the expedition’s survival in part to a single cannon loaded with horseshoe fragments cut down to serve as canister shot when conventional ordnance ran short (Leeson; Vowell). Whatever the precise chain of custody, by the middle of the decade this weapon, or the legend attached to it, had become fixed in the minds of Yellowstone valley trappers as the Bighorn gun.

Fort Pease and a Fragile Foothold

The gun found its operational home at Fort Pease, a trading post established in June 1875 a few miles below the mouth of the Bighorn River by a party of Bozeman businessmen (Historical Marker Database). The post took its name from Major Fellows D. Pease, an experienced Indian trader and former Crow agency employee who led the venture, and its backers hoped the location would become the head of steamboat navigation on the Yellowstone—a foothold from which to capture trade with the Crow tribe and position themselves ahead of the Northern Pacific Railroad’s advance (Historical Marker Database; "Fort Pease, Montana"). The stockade itself was modest: a cluster of cottonwood log huts joined by a palisade enclosing a square of roughly one to two hundred feet, depending on the source consulted ("Fort Pease, Montana"; Montana Trappers Association). Paul McCormick, one of the traders present, later recalled the settlement forming on the east side of the Bighorn near its junction with the Yellowstone, close to a site where an earlier party had staked out a town called Bighorn City in 1863 (McCormick).

The location was, in retrospect, reckless. It sat squarely within hunting grounds the Lakota regarded as their own under the terms of the 1868 treaty—land the government had promised to keep free of unauthorized settlement (Historical Marker Database; "Fort Pease, Montana"). The traders who built Fort Pease were not government surveyors or soldiers; they were private citizens gambling that a river crossing and a fortified trading house could turn a profit before anyone with authority to stop them intervened. It was here, inside this exposed outpost, that the Bighorn gun was mounted as the post’s sole piece of heavy weaponry (Leeson).

Siege on the Yellowstone

The peace did not hold. Sources differ slightly on the exact date hostilities began, a reminder that frontier chronology recorded after the fact rarely lines up with precision. Leeson’s account places a major attack on the night of July 10, while Paul McCormick’s later reminiscence suggests the group did not reach the site until August or September of 1875 (Leeson; McCormick). What is corroborated across multiple accounts is the severity of the fighting. Through the winter of 1875 into 1876, Lakota warriors kept the post under near-constant harassment, and by the time help arrived the trappers had suffered six men killed and eight wounded—figures repeated consistently in both the Fort Pease historical marker text and McCormick’s firsthand account (Historical Marker Database; McCormick).

Conditions grew dire enough that the besieged traders sent word to Fort Ellis, the army post near Bozeman, pleading for relief. In early March 1876, Major James S. Brisbin arrived with four companies of the Second Cavalry and lifted the siege (Historical Marker Database). McCormick’s account adds a specific tally to the relief: of the post’s roughly forty-six original members, six were dead, eight wounded, thirteen had escaped on their own before help came, and Brisbin escorted the remaining nineteen survivors back to Bozeman (McCormick).

Relief, Survival, and Preservation

Brisbin’s orders were to withdraw the trappers, not to garrison the post. On March 6, 1876, the cavalry and traders marched west, leaving Fort Pease standing empty. Contemporary observers assumed the Lakota would burn the stockade to the ground as soon as it was abandoned.

However, frontier assumptions proved wrong. When Colonel John Gibbon’s "Montana Column" descended the Yellowstone on April 19, 1876, during the opening maneuvers of the Great Sioux War, soldiers were surprised to find Fort Pease standing intact. The American flag left by the traders was still flying over the ramparts, and a stray dog greeted the arriving troops. Gibbon occupied the post for roughly two weeks, using its stockade for storage, shelter, and scouting operations along the Bighorn corridor before advancing downriver. Though the wooden stockade eventually succumbed to decay and later fires after the campaign ended, it did not burn upon the initial retreat.

More significantly, the Bighorn gun itself survived the venture. Transported back to the Gallatin Valley alongside the retreating traders, the iron piece retired from active warfare to become a celebrated civic relic. Union and Northern Pacific interests continued eyeing the Bighorn and Yellowstone confluence as a transportation hub, and Paul McCormick himself returned to the valley in 1877 with Major Pease to open a permanent store, famously raising an American flag over the resettled grounds (McCormick).

Assessing a Frontier Legend

Historians working with sources like these face a familiar problem: the surviving record blends firsthand recollection, secondhand correspondence quoted in nineteenth-century compilations, and popular local lore. The core facts of the Bighorn gun’s story—its origin on the Bozeman Trail corridor by 1870, its service with the 1873 brown expedition, its installation as Fort Pease’s sole defense in 1875, and its subsequent rescue—are corroborated across independent sources, including military field journals, regional historical markers, and participant memoirs.

Far from being melted down into scrap metal in the ashes of the fort, the original iron barrel of the Bighorn gun was preserved by Southwest Montana pioneers. Today, the infamous cannon stands on permanent public display outside the Gallatin History Museum (formerly the Pioneer Museum) in downtown Bozeman, Montana.

What remains is a story about improvisation on a dangerous frontier: a worn cannon, repurposed ammunition, and a fort built on ground its occupants had no legal claim to. The gun the mountaineers idolized could not save Fort Pease as a commercial enterprise, but its physical presence endures as an authentic artifact of the Montana territory's defining decade.

Works Cited

Buckley, Jay H. “Bozeman Trail.” Encyclopedia of the Great Plains, Plains Humanities, University of Nebraska-Lincoln, plainshumanities.unl.edu/encyclopedia/doc/egp.tra.005.html.

“Fort Pease Historical Marker.” Historical Marker Database (HMDB #165326), Custer Circle Project and City of Hysham, 2017, hmdb.org/m.asp?m=165326.

“Fort Pease, Montana.” Legends of America, [legendsofamerica.com/fort-pease-montana/](https://legendsofamerica.com/fort-pease-montana/).

“Fort Pease.” BigSkyTreasure History Archives, bigskytreasure.org/history/places/fort-pease.

“Fur Posts in Montana.” Montana Trapper’s Association, montanatrappers.org/basics/history/fur-posts.html.

Gallatin History Museum. "Permanent Exhibits: The Big Horn Gun," Gallatin Historical Society, Bozeman, MT, gallatinhistorymuseum.org.

Gibbon, John. Official Report of the Montana Column: April–June 1876. Montana Historical Society Research Center Archives.

Leeson, Michael A. History of Montana, 1739-1885: A History of Its Discovery and Settlement, Social and Commercial Progress. Warner, Beers & Co., 1885.

McCormick, Paul. “Sheep and Cattle on the Crow Reservation.” Yellowstone Genealogy Forum, (https://sites.rootsweb.com/~mtygf/county/mccormick.htm).

National Park Service. “Chronology of Bighorn Canyon History, Part Two: 1864-1968.” Bighorn Canyon National Recreation Area, nps.gov/bica/historyculture/chronology-of-bighorn-canyon-history-part-two-1864-1968.htm.

Vowell, Sarah. "Shooting Dad." The Opposite of Fate: Memories of a Writing Life, Penguin Books, 2003 (Documenting the history and current display of the Big Horn Gun at the Pioneer Museum in Bozeman).