EDGERTON COUNTY, MT HISTORY AND LOOKUP (EXTINCT COUNTY, 1865-1867)

County History Books

*None Listed

Edgerton County, Montana: A Genealogical Overview

As one of the nine original counties created by the first Montana Territorial Legislature, Edgerton County existed for only two years during the chaotic peak of the Montana gold rush. Its story is the story of the founding of Helena and the explosive growth that followed the discovery of gold at Last Chance Gulch. Named for Montana’s first territorial governor, its swift renaming was a political act that did not alter its boundaries or its records. For the genealogist, researching this short-lived county means focusing entirely on the earliest records of its direct and permanent successor, Lewis and Clark County.

I. County Formation and Evolution

Understanding Edgerton County’s identity as the direct predecessor to Lewis and Clark County is the single most important factor for locating family records. The records are continuous; only the name on the courthouse door changed.

  • 1865: County Formed: Edgerton County was established on February 2, 1865, by the first legislative assembly of the newly formed Montana Territory.
  • Parent Entity: It was created from unorganized territory that had briefly been part of Idaho Territory (1863-1864) and, before that, Dakota and Nebraska Territories. Records prior to 1865 are exceptionally scarce and would be found in the records of those larger parent territories.
  • Dissolution and Successor County: Sidney Edgerton, the county’s namesake and territorial governor, was a controversial figure. After he left the territory, the politically opposed legislature acted to remove his name from the map. On February 16, 1867, Edgerton County was officially renamed Lewis and Clark County. The boundaries, county seat, and all official records remained intact. All records created during the Edgerton County period (1865-1867) are now considered the earliest records of Lewis and Clark County.
  • Name Origin: The county was named for Sidney Edgerton (1818-1900), a former Ohio congressman appointed by Abraham Lincoln as the Chief Justice of the Idaho Territory and who became the first Territorial Governor of Montana.
  • County Seat History: The initial, temporary county seat was designated as Silver City. However, the immense gold strike at Last Chance Gulch in 1864 had already established Helena as the region’s undeniable population and commercial hub. The county seat was officially moved to Helena in September 1865, where it has remained for its successor, Lewis and Clark County, ever since.

II. Settlement and Early History

  • Early Inhabitants: The Prickly Pear Valley and surrounding lands were the traditional territories of several Native American tribes, including the Salish, Kootenai, and Blackfeet peoples.
  • The Gold Rush and Settlement: European-American settlement was virtually nonexistent before the gold rush. The catalyst for the county’s creation was the discovery of rich placer gold deposits in Last Chance Gulch (in the heart of modern-day Helena) on July 14, 1864, by a group of four prospectors known as the “Four Georgians.” This discovery triggered a massive influx of miners, merchants, and fortune-seekers. The settlement of Helena grew from a handful of cabins to a bustling town of thousands within a year. The early economy was entirely dependent on gold mining, with freighting, farming, and logging emerging to support the boomtown.
  • Law and Order: The period was characterized by the transition from the rough frontier justice of the Montana Vigilantes (who were most active just prior to the county’s formation) to the establishment of formal courts and law enforcement under a territorial government.

III. Genealogical Records and Resources

This section provides practical information for locating ancestral records, all of which will be found under the name “Lewis and Clark County.”

  • County Courthouse (Successor Repository): No records are filed under the “Edgerton County” name. All records from 1865 onward are held by the Lewis and Clark County government.
    • Lewis and Clark County Clerk and Recorder: Located at 316 N Park Ave, Helena, MT 59623. This office holds all land and property records (deeds, mining claims, mortgages) from 1865 to the present.
    • Clerk of the District Court: Located in the Lewis and Clark County Courthouse, this office holds all judicial records, including civil and criminal cases, probate records (wills, estates), and, crucially, marriage records from 1865.
  • Vital Records:
    • Birth and Death Records: Statewide registration of births and deaths was not required in Montana until 1907. Records prior to this date are extremely rare. Some may be found in the early records of the Clerk of the District Court or within church registers.
    • Marriage Records: Marriage licenses and certificates from 1865 to the present are held by the Clerk of the District Court for Lewis and Clark County.
  • Libraries and Societies:
    • Montana Historical Society Research Center: This is the single most important destination for Montana genealogical research. Located in Helena (225 N. Roberts St.), its archives contain an unparalleled collection of early Montana newspapers on microfilm, manuscript collections, state and county government records, photographs, and vital records indexes.
    • Lewis & Clark Library: The Helena branch has a local history collection with books and other materials pertaining to the area’s history.
  • Bordering Jurisdictions (1865-1867):
    • Deer Lodge County (west)
    • Missoula County (northwest)
    • Chouteau County (north and east)
    • Gallatin County (southeast)
    • Jefferson County (south)

Please share any resources you have and will do lookups or links to resources you are aware of. Thanks