The First Line on the Map:

How a Virginia-Born Engineer Charted Montana Territory in 1865

Introduction

In the winter of 1865, a civil engineer working out of a raw mining territory carved from the northern Rocky Mountains finished a document that no government body had ever before commissioned for that ground: an authorized map of Montana. The engineer was Walter Washington De Lacy, and the map he produced, printed that year in St. Louis by the lithographer Julius Hutawa, gave the year-old Territory of Montana its first official cartographic likeness. It was a modest-looking sheet by the standards of later surveys, yet it carried real administrative weight. Montana's first territorial legislature had ordered it into existence for a specific purpose: to help lawmakers see, and therefore divide, a territory most of them had never fully traveled. The map's story is inseparable from the story of the man who drew it, and both are documented, with occasional gaps and small contradictions, in archival and cartographic records that survive today.

An Engineer Arrives in the West

De Lacy was born in Petersburg, Virginia, on February 22, 1819, and spent his boyhood in Norfolk after his parents died young, raised by aunts and uncles (Archives West). As a teenager he attended Mount St. Mary's Catholic College in Emmitsburg, Maryland, graduating in 1838. The following year he sought an appointment to the United States Military Academy at West Point, but the appointment was revoked because of a clerical error. Rather than abandon the ambition, De Lacy arranged for private instruction at West Point in mathematics, surveying, civil engineering, and topography, and began his professional life as an engineer at twenty (Archives West). This detail matters because at least one later commercial source describes De Lacy simply as "a civil engineer and West Point graduate," a claim not supported by the archival finding aid held by the Montana Historical Society, which specifies private tutoring rather than a completed cadetship (Ruderman). Where the two accounts diverge, the archival record, drawn from De Lacy's own papers, is the more reliable of the two, and this article follows it.

De Lacy's engineering career carried him through military road work in the Pacific Northwest, including service under Lieutenant John Mullan on the wagon road across the northern Rockies, before he turned to prospecting. In August 1863 he was in Virginia City, in what was then Idaho Territory, and joined a small party of prospectors bound for the upper Snake River country. The expedition pushed north into the geyser basins of what would become Yellowstone National Park, and De Lacy is credited with locating the lake that still bears his name, Shoshone Lake, then commonly called De Lacy's Lake (American Surveyor). These wanderings gave him a working knowledge of terrain that few of his contemporaries could match, knowledge that would later inform his cartography.

A Territory Orders Its Own Portrait

Montana Territory was carved out of Idaho Territory by act of Congress on May 16, 1864. Its first legislative assembly convened that summer at Bannack, then serving as territorial capital, a mining camp that had sprung up around a gold strike only two years earlier. Among the assembly's practical problems was the absence of any reliable map showing where the territory's people, mining districts, and natural boundaries actually lay, information the legislature needed in order to lay out counties. The assembly directed De Lacy, already known locally for his engineering work and his role laying out the townsite of Fort Benton in 1864, to compile such a map (Archives West; American Surveyor). Both the archival finding aid and the professional-society account of De Lacy's career agree on this basic sequence of events, which lends it reasonable confidence despite the absence of a surviving legislative journal entry quoted directly in either source.

De Lacy did not conduct an original ground survey of the entire territory for this commission. Instead, he compiled the map from existing information: notes from his own travels, data gathered from miners, prospectors, and other surveyors working the gulches, and whatever government survey material was available for the surrounding region, including earlier railroad reconnaissance work associated with Isaac Stevens's Pacific railroad surveys of the 1850s (Ruderman). This method, common enough among nineteenth-century territorial cartographers working with limited time and no dedicated survey corps, meant the resulting map reflected a patchwork of secondhand testimony as much as it did direct measurement. That De Lacy managed to assemble a coherent and reasonably useful document from such fragmentary sources speaks to his engineering training and his personal familiarity with the region's mining camps.

Compiling the Map

De Lacy completed the compilation in February 1865, working from Virginia City. According to the account preserved by the map dealer Barry Lawrence Ruderman, drawing on the cartographic historian Rodney Saunders's article in the journal Imago Mundi, De Lacy produced two manuscript copies of the map, one of which was shipped east for printing (Ruderman). This detail about the two manuscript copies appears only in this single source among those consulted for this article, and it should be treated as plausible but not independently corroborated. What is corroborated across multiple sources is the eventual printer: the St. Louis lithography firm of Julius Hutawa produced the first printed edition in 1865, carrying the full title Map of the Territory of Montana with Portions of the Adjoining Territories, Showing the Gulch or Placer Diggings Actually Worked and Districts Where Quartz (Gold & Silver) Lodes Have Been Discovered to January 1st 1865 (Library of Congress; Yale University Library).

That title is worth pausing over, because it reveals what the map's original audience most wanted to see. This was, first and foremost, a mining document. The territory's political and economic life in 1865 revolved almost entirely around placer and quartz gold production in gulches such as Alder Gulch and Last Chance Gulch, and De Lacy's map made the location of active diggings and mineral districts its organizing feature, alongside the county boundaries the legislature had requested. The map's scale, roughly 1:1,500,000, covered a broad swath of country: Montana Territory itself along with adjoining portions of Wyoming, Idaho, and Dakota country, since territorial boundaries in the region remained in flux and mining traffic routinely crossed them (Yale University Library). A surviving copy at the Beinecke Rare Book and Manuscript Library at Yale bears the ownership mark of an early geologist, B. F. Shumard, evidence of the map's circulation among scientifically minded users beyond Montana itself (Yale University Library).

Reception and Later Editions

The 1865 Hutawa printing was not De Lacy's last word on the subject. Within a few years, new information from continued survey work and from expeditions into the Yellowstone country prompted revisions. An enlarged edition was issued by the New York firm G. W. and C. B. Colton in 1870, and a further revised Colton edition followed in 1872, both incorporating material not available at the time of the original 1865 compilation, including additional road networks in Idaho and eastern Washington (Ruderman). These later editions added detail on military posts, Indian agencies and reservations, and emigrant and freight routes such as the Bridger and Bozeman trails, though how much of that specific content appeared already in 1865 versus only in the later Colton revisions is not entirely clear from the surviving dealer descriptions, which tend to describe the map's cumulative history rather than isolating each edition's individual contents. Readers should understand the 1865 Hutawa map and the 1870s Colton maps as related but distinct documents in an evolving series, not as a single static image.

The cartographic historian Carl I. Wheat, whose multivolume study of Trans-Mississippi mapping remains a standard reference in the field, called the De Lacy map one of the notable achievements in the record of western American cartography, praising it for its treatment of both the Montana mining country and the then little-known Yellowstone region (Ruderman). This assessment, reached secondhand through Ruderman's gallery description rather than direct consultation of Wheat's original text, should be read as a respected outside judgment rather than an uncontested consensus, since it comes from a single citation chain.

De Lacy's Later Career

De Lacy did not retire from public work after 1865. He platted the townsites of Deer Lodge and Argenta later that same year, and by 1867, during tensions with Sioux bands in the region, Acting Territorial Governor Thomas Francis Meagher commissioned him a colonel of engineers (Archives West). From 1867 to 1871 he worked in the office of the territorial Surveyor General, producing maps in support of the Northern Pacific Railroad's planning, and he later served as Helena's city engineer and as chief clerk to the federal Surveyor General, a post he held until his death on May 13, 1892 (Archives West). He was a founding or charter member of several professional and historical organizations in the territory, including the Montana Society of Civil Engineers, the Society of Montana Pioneers, and the Historical Society of Montana itself, an institution that today preserves much of the documentary record on which this account depends (Archives West).

Conclusion

The 1865 De Lacy map endures less as a triumph of precise measurement than as a record of what a newly formed territory most urgently needed to know about itself: where the gold was, where the people had settled, and where the lines of counties might reasonably be drawn across country still only partially explored by its own government. It was compiled quickly, from imperfect sources, by a man whose formal credentials were themselves the subject of some later exaggeration. Yet it served its purpose, went through several revised editions over the following decade, and survives today in research libraries from Helena to New Haven as the starting point of Montana's official cartographic record.

Works Cited

Archives West. "Walter Washington De Lacy Papers, 1855-1896." Montana Historical Society Research Center Archives, Orbis Cascade Alliance, archiveswest.orbiscascade.org/ark:/80444/xv54042. Accessed 28 July 2026.

De Lacy, W. W. Map of the Territory of Montana with Portions of the Adjoining Territories: Showing the Gulch or Placer Diggings Actually Worked and Districts Where Quartz (Gold & Silver) Lodes Have Been Discovered to January 1st 1865. Jul. Hutawa, 1865. Library of Congress, www.loc.gov/item/2006629627/. Accessed 28 July 2026.

De Lacy, W. W. Map of the Territory of Montana with Portions of the Adjoining Territories, Drawn by W.W. de Lacy for the Use of the First Legislature of Montana. 1865. Beinecke Rare Book and Manuscript Library, Yale University Library, brbl-dl.library.yale.edu/vufind/Record/4211699. Accessed 28 July 2026.

"In Memoriam, Walter Washington de Lacy." Journal of the Association of Engineering Societies, vol. 18, no. 6, June 1897. Montana History Portal, Butte-Silver Bow Public Library, www.mtmemory.org/nodes/view/5784. Accessed 28 July 2026.

"Initial Point of Montana." The American Surveyor, 1 Feb. 2014, amerisurv.com/2014/02/01/initial-point-of-montana/. Accessed 28 July 2026.

Montana Historical Society. "Map: Montana Territory Map, 1865." Montana Historical Society Store, app.mt.gov/shop/mhsstore/map-montana-territory-map-1865-10. Accessed 28 July 2026.

"Map of the Territory of Montana with Portions of the Adjoining Territories... Helena, M.T. 1870." Barry Lawrence Ruderman Antique Maps Inc., www.raremaps.com/gallery/detail/28747/map-of-the-territory-of-montana-with-portions-of-the-adjoini-de-lacy. Accessed 28 July 2026.