Big Horn County, Wyoming Genealogy Records

Selected record inventories for Big Horn County, their listed years, and where to ask for access.

Selected inventory review: 2026-11-02. Selected repository catalog metadata reviewed. This is not a complete holdings audit or certification of current access. See the repository note for limitations. Official repository catalog or holdings guide

Formed
1890
County seat
Basin
Campbell CountyConverse CountyCrook CountyHot Springs CountyNatrona CountyNiobrara CountyPark CountyPlatte CountySublette CountyWashakie CountyWeston CountyFremont CountyJohnson CountySheridan CountyBig Horn CountyCampbellConverseCrookHot SpringsNatronaNiobraraParkSubletteWashakieWestonFremontJohnsonSheridanBig Horn
Big Horn CountyParent counties (search here for earlier records)Today's boundaries · U.S. Census Bureau

Listed record inventories

Selected holdings and indexes for Big Horn County, checked against the repository descriptions linked below. Date spans may contain gaps; an index is not a complete set of original records.

Court records

See the repository's descriptions and search options

Repository access note: Collection-level court records described by Wyoming State Library guides to State Archives holdings. Date spans may contain gaps and are not inventories of every case or series. Links lead to the verified guide; its external finding-aid host was not accessible during this review. Confirm case numbers, restrictions and custody with the Archives or court.

Sources: the catalogs and repository descriptions linked on the entries above. Selected inventories do not establish complete coverage of every record type or online access to original documents. Read the repository access note for source dates and limitations.

Where to find the records

  • Big Horn County official website

    Hours, addresses and phone numbers for the county clerk and the clerk of the district court, and any online record search the county offers.

  • The county clerk

    Deeds and other land records, and marriage licenses.

  • The clerk of the district court

    Probate (wills and estates), divorces and court cases.

  • The Wyoming State Archives

    In Cheyenne: county and territorial records and newspapers.

  • Wyoming State Archivesfree

    The state archives in Cheyenne, with county and territorial records, newspapers and photographs.

  • FamilySearch Catalogfree

    Search by place for "Wyoming, Big Horn" to find filmed and digitized records, many viewable free online with a FamilySearch account.

Offices change their hours and access rules; call before you visit.

Boundaries and parent counties

Formed from: Fremont County, Johnson County, Sheridan County

Check the parent counties for earlier records: Fremont County, Johnson County, Sheridan County

Later formed partly from Big Horn County: Hot Springs County, Park County, Washakie County

UintaCrookSweetwaterAlbanyCarbonNatronaConverseLaramieFremontJohnsonSheridanBig HornBig HornFremontJohnsonSheridanUintaCrookSweetwaterAlbanyCarbonNatronaConverseLaramie
Big Horn as created in 1890Where its land was the day beforeToday's boundaryBoundaries: Newberry Library, Atlas of Historical County Boundaries

Records stay with the county that created them. If your ancestor lived here before 1890, search the parent county. The Atlas of Historical County Boundaries shows each boundary change.

Research tip

Wyoming began statewide registration of births and deaths in 1909. Before 1868 its land was part of Dakota, Idaho, Utah and other territories.