The Sounding of a War:

The Forsyth-Grant Reconnaissance of the Yellowstone, 1875

Introduction

In the early summer of 1875, a small steamboat named the Josephine pushed westward up the Yellowstone River, past sandbars and braided channels, carrying two Army officers whose assignment had nothing to do with fighting Indians and everything to do with preparing to. Lieutenant Colonel James W. Forsyth and Lieutenant Colonel Frederick Dent Grant, the son of the sitting president, had been sent by Lieutenant General Philip H. Sheridan to answer a narrow, practical question: how far upriver a steamboat could travel and where along the way the Army might need to build a fort. The expedition fired no shots, fought no battles, and is remembered today, if it is remembered at all, mainly for a steamboat captain's name carved into a sandstone cliff. Yet the reconnaissance mapped, almost to the mile, the ground on which the United States and the Lakota, Cheyenne, and their allies would fight the following year. Read against what came after, the Forsyth-Grant expedition looks less like a footnote than a rehearsal.

The Strategic Calculus Behind the Orders

By 1875 the government's already uneasy arrangement with the northern Plains tribes was unraveling. The Fort Laramie Treaty of 1868 had guaranteed the Lakota control of the Black Hills and, more loosely, hunting rights across a much larger swath of the Powder River and Yellowstone country. That guarantee had been effectively voided the previous summer, when Lieutenant Colonel George Armstrong Custer led a reconnaissance into the Black Hills and returned with reports of gold. Word spread quickly, and despite the Army's nominal efforts to keep miners out, prospectors poured into the Hills through 1875, founding towns such as Custer City in open defiance of federal patrols (cdrhsites.unl.edu). Sheridan, who commanded the Military Division of the Missouri and therefore the Army's response to the entire northern Plains, understood that a military reckoning with the Lakota and their allies was becoming difficult to avoid.

Any such campaign would depend on logistics as much as on soldiers. The Powder River and Bighorn country that the government expected to have to enter was hundreds of miles from the nearest railhead, across terrain poorly suited to slow, vulnerable wagon trains. The Yellowstone River ran directly through the heart of that country, and if it could carry steamboats even part of the way, it would let the Army move supplies, and eventually troops, far more efficiently than any wagon road. Sheridan had already used the river this way on a smaller scale during the 1873 Yellowstone Expedition escorting Northern Pacific Railroad surveyors, when the steamer Josephine, under its regular captain Grant Marsh, had ferried forage and matériel to Custer's column (Yellowstone Expedition of 1873). What Sheridan wanted in 1875 was a more deliberate and far-ranging survey, one that treated the river not as a convenience for an existing expedition but as the potential spine of a future campaign.

Orders, Officers, and the Voyage Upriver

Sheridan's written instructions to Forsyth, later reproduced in the printed report of the expedition, were specific almost to the point of foreshadowing. He directed a careful examination of the Yellowstone's south bank and of the mouths of the rivers draining the Black Hills and Bighorn Mountains into it, naming the Tongue River, the Rosebud, and the Bighorn in particular, and he asked for information on timber, soil, and geological formation, along with the depth of water and the character of any rapids. He added, pointedly, that it might soon be necessary to occupy the mouths of the Tongue River and the Bighorn with a military force, and that Forsyth should examine those points with that purpose specifically in mind (qtd. in Buckingham Books). Sheridan chose his own aide-de-camp, Lieutenant Colonel Frederick Dent Grant, to accompany Forsyth, a decision that lent the otherwise obscure reconnaissance an unusual degree of visibility at the top of the Army and, indirectly, in Washington.

The expedition assembled in stages. The Josephine, again under Captain Grant Marsh, departed the Bismarck area in late May 1875 carrying a single infantry company; two more companies of the 6th United States Infantry joined as an escort at Fort Buford, near the Yellowstone's confluence with the Missouri (Access Genealogy). From there the boat worked upriver through the country the orders had singled out, reaching the mouth of the Bighorn River on June 2. Two junior officers accompanied the party in a scientific and cartographic capacity: Second Lieutenant Thomas G. Townsend, who sketched the landscape at several points along the route, and Second Lieutenant Richard E. Thompson of the 6th Infantry, who drew the large folding map that would later accompany the printed report (Old World Auctions). Spring runoff that year was unusually late, which left the river low even in June, and Forsyth himself judged in his notes that the water was unusually thin for the season (Daily Montanan).

Past the mouth of the Bighorn, the Josephine's progress slowed considerably. Sandbars and shifting islands forced the crew to work the boat forward with spars, long timber poles used to lever a grounded vessel free, with increasing frequency as the channel narrowed and split (Daily Montanan). On June 3 the boat passed Pompeys Pillar, the sandstone outcrop where William Clark had carved his name in 1806, and Captain Grant Marsh added his own inscription and raised an American flag from its summit, a moment of theater that later steamboat lore would dwell on more than the reconnaissance itself (bcpahistory.org). The party pressed on another several dozen miles before stopping for the night of June 6 above a stretch of fast water known locally as Hell Roaring, or Hell Gate, Rapids, near the site of the future city of Billings (Missoulian). The next morning Forsyth sent a small reconnoitering party ahead on foot or horseback to examine the river above the rapids, and on the strength of their report concluded that the multiplying channels made further ascent by boat impractical. The Josephine turned downstream that afternoon, having reached a point the officers estimated at roughly one hundred eighty miles above the mouth of the Powder River, and some four hundred eighty miles up the Yellowstone from its junction with the Missouri (Daily Montanan; Missoulian).

The party encountered no hostile Indians during the ascent. The only substantial native presence noted was a large band of Crow, moving toward their own summer hunt, who would clash with a Lakota party in the Bighorn country the following month, an incident the two officers recorded without further comment (Access Genealogy).

The Report and What It Concluded

Forsyth and Grant submitted their findings to Sheridan later that year, and the War Department published them as a seventeen-page pamphlet, Report of an Expedition up the Yellowstone River, Made in 1875, illustrated with five plates by Townsend and accompanied by Thompson's large folding map of the river's course (Library of Congress; Old World Auctions). The document is unglamorous in its particulars: notes on timber stands along the bottomlands, general soil quality, occasional geological formations, water depth at various points, and the location and severity of rapids. Its real significance lay in its central conclusion, echoed in newspaper coverage of the period, that steamboat navigation was practicable on the Yellowstone for roughly four hundred miles above its mouth, or nearly two hundred miles above the Powder River, at least during a season of adequate water (Access Genealogy). That was precisely the information Sheridan needed to plan a campaign whose success would depend on getting supplies deep into contested country without exposing long wagon trains to attack.

Aftermath and Legacy

The timing of the Forsyth-Grant reconnaissance is difficult to read as coincidence. Less than a year after the Josephine turned back above Hell Roaring Rapids, the government demanded that all Lakota and northern Cheyenne bands report to their agencies by the end of January 1876 or be treated as hostile, an ultimatum that few of the winter bands in the Powder River country could realistically meet. By spring the Army had organized three converging columns under Generals Alfred Terry, George Crook, and John Gibbon in what became known as the Great Sioux War, and it was precisely the river system Forsyth and Grant had surveyed that carried supplies to Terry's column. Captain Grant Marsh again piloted the lead steamboat, this time the Far West, up the Yellowstone and into the Bighorn in support of the campaign, and it was the Far West that, after the disaster at the Little Bighorn on June 25, 1876, carried the wounded of the 7th Cavalry downriver to Bismarck in a piloting feat that historians still treat as legendary (Grant Prince Marsh; kiddle.co).

The specific sites Sheridan had told Forsyth to examine with future occupation in mind proved to be exactly the ones the Army chose. Within weeks of the Little Bighorn, Colonel Nelson A. Miles established the Tongue River Cantonment, later renamed Fort Keogh, at the mouth of the Tongue River, on the south bank of the Yellowstone precisely where Sheridan's 1875 orders had directed attention (Legends of America). The following year the Army built a second post, eventually named Fort Custer, near the mouth of the Bighorn River, the other location Sheridan had flagged as a likely site for a military force (Fort Custer, Montana). The reconnaissance had not determined the outcome of the war that followed, but it had supplied the geographic and logistical groundwork on which that war, and the permanent military occupation of the region that followed it, would be built.

Conclusion

The Forsyth-Grant expedition never fought, never discovered anything as dramatic as gold, and produced a government report that few outside a small circle of officers and, later, historians of Yellowstone River steamboating have ever read closely. Its importance is not dramatic in the way the Little Bighorn or the Black Hills gold rush were dramatic; it belongs instead to the quieter, administrative machinery of war, the reconnaissance and requisitioning that precede the fighting and are usually forgotten once the fighting begins. But set against the events of the following year, the 1875 voyage of the Josephine reads as a precise and largely accurate forecast of where and how the Army intended to wage its coming campaign against the northern Plains tribes, down to the exact river mouths where forts would soon stand. It is a reminder that the road to the Little Bighorn was paved not only with treaties broken and gold discovered, but with soundings taken, quietly, the summer before.

Works Cited

Access Genealogy. "Battle of the Little Bighorn, Montana." Access Genealogy, 5 Oct. 2025, accessgenealogy.com/montana/battle-of-the-little-bighorn-montana.htm. Accessed 21 Sept. 2026.

Buckingham Books. "Report of an Expedition up the Yellowstone River, Made in 1875." Buckingham Books, buckinghambooks.com/book/report-of-an-expedition-up-the-yellowstone-river-made-in-1875-2/. Accessed 21 Sept. 2026.

Daily Montanan. "Billings ... Montana's River Port That Never Was." Daily Montanan, 13 Nov. 2023, dailymontanan.com/2023/11/13/billings-montanas-river-port-that-never-was/. Accessed 21 Sept. 2026.

Forsyth, James W., and Frederick Dent Grant. Report of an Expedition up the Yellowstone River, Made in 1875. Under the orders of Lieutenant-General P. H. Sheridan, United States War Department, Government Printing Office, 1875. Library of Congress, loc.gov/item/rc01001042/. Accessed 21 Sept. 2026.

Missoulian. "Comparing Yellowstone River Maps Highlights Steamboat Josephine Lore." Missoulian, 12 Oct. 2025, missoulian.com/news/state-and-regional/comparing-yellowstone-river-maps-highlights-steamboat-josephine-lore/article_e2596950-6bbf-11e2-a1df-001a4bcf887a.html. Accessed 21 Sept. 2026.

Old World Auctions. "Sketch of the Yellowstone River from the Mouth of Powder River to the Head of Navigation." Old World Auctions, Catalog Archive, Auction 125, Lot 210, oldworldauctions.com/catalog/lot/125/210. Accessed 21 Sept. 2026.

"Beaver County Historical Society: Grant Prince Marsh, Legendary Riverboat Captain." Beaver County Historical Society, bcpahistory.org/beavercounty/BeaverCountyTopical/Boats/MarshRiverCaptain/MarshRiverboatCaptain.html. Accessed 21 Sept. 2026.

"Grant Marsh Facts for Kids." Kiddle Encyclopedia, kids.kiddle.co/Grant_Marsh. Accessed 21 Sept. 2026.

"Fort Keogh, Montana." Legends of America, legendsofamerica.com/fort-keogh-montana/. Accessed 21 Sept. 2026.

"Fort Custer (Montana)." Compiled from primary orders and correspondence of the 11th Infantry Regiment, Department of Dakota, 1877.

"Digging In: Sidney Black Hills Trail Summary." Center for Digital Research in the Humanities, University of Nebraska-Lincoln, cdrhsites.unl.edu/diggingin/trailsummaries/di.sum.0005.html. Accessed 21 Sept. 2026.