Colorado Historical Societies

This directory lists 6 historical societies, museums, and archives in Colorado, including the Denver Public Library Western History Collection, the Colorado Railroad Museum in Golden, and the Molly Brown House Museum in Denver. Each card links to a page with the organization's address, website, and what it collects, so you can decide where to write or visit before you start.

Colorado was organized as a territory in 1861 from pieces of Kansas, Nebraska, Utah, and New Mexico territories and became a state on August 1, 1876. That timeline shapes the records: anyone living here in 1860 was counted in the Kansas or Nebraska territorial census, the first counties date from 1861, and the state did not require birth and death registration until 1908. Many families came for a gold strike or a homestead and moved on within a decade, so expect to follow them through several counties and sometimes into Wyoming or New Mexico.

Featured Historical Societies

Major repositories in Colorado

Start with the Colorado State Archives, 1313 Sherman Street, Room 1B-20, Denver, which holds state and county government records back to the territorial period. The series genealogists use most are the county birth and death registers kept before statewide registration, a statewide marriage index, school records, Colorado military records, and state penitentiary records. Visits are by appointment only, and the reference desk (303-866-2358) is staffed Tuesday through Friday, 10:00 a.m. to 4:00 p.m. Mountain time. Records more than 100 years old are treated as historic and can usually be viewed without proving a relationship. Colorado State Archives website.

• History Colorado, the state historical society, operates the History Colorado Center in Denver and houses both the state historic preservation office and the Stephen H. Hart Research Center, its library of photographs, manuscripts, and Colorado history.
• Denver Public Library Special Collections and Archives (long known as the Western History and Genealogy Department) at the Central Library, 10 W. 14th Avenue Parkway, is the largest public-library collection on the Rocky Mountain West. Search its digital collections (digital.denverlibrary.org) and online finding aids (archives.denverlibrary.org) before you visit; the Blair-Caldwell African American Research Library is a companion branch. Denver Public Library Special Collections
• The Colorado State Library in Denver is a service agency rather than a reading room, but it funds and runs the Colorado Historic Newspapers Collection described below.
• The National Archives at Denver (in Broomfield) is where the FamilySearch wiki sends Colorado researchers for federal land entry case files and for the records of federal courts and agencies in the region.

Birth, death, marriage, and divorce records

Colorado did not require counties to register births and deaths until 1908, and compliance stayed uneven into the 1920s. The county registers kept between 1876 and 1907 are incomplete, and two counties, Conejos and Douglas, lost records outright. Surviving pre-1908 birth and death registers are at the Colorado State Archives, not at the health department.

Certified copies of later certificates come from the Vital Records Section of the Colorado Department of Public Health and Environment (CDPHE), 4300 Cherry Creek Drive South, Denver. The state office holds death records from 1900 and birth records from 1910, plus earlier births for some counties. Access is restricted: a birth record opens to the public after 100 years and a death record after 75; before that you must document a direct relationship. CDPHE Vital Records

• Marriages were recorded by the county clerk from the date each county was organized; there was no early statewide register, though the State Archives maintains a marriage index. Couples usually married in the bride's home county, and some crossed into a neighboring state, so widen the search if the county turns up nothing.
• Divorces are district court cases. Ask the clerk of the district court in the county where the suit was filed; older district court records from some counties have been transferred to the State Archives.

Land, deeds, mining claims, and homesteads

Colorado is a public-land state: nearly all title originated with the federal government, apart from a handful of Spanish and Mexican land grants in the San Luis Valley and along the southern border that the U.S. Surveyor General processed between 1855 and 1890. Records of those grants are at the Bureau of Land Management's New Mexico State Office in Santa Fe, because the New Mexico office handled them before 1862.

• Federal patents (homesteads, cash sales, and mineral patents) are searchable by name and legal description at the BLM General Land Office Records site, which also serves survey plats. The land entry case file behind a patent, with the claimant's affidavits and witness statements, is a National Archives record.
• Mining claims were located and recorded at the county level, so lode and placer claim books, mining deeds, and proof-of-labor affidavits sit with the County Clerk and Recorder, next to ordinary deeds and mortgages. A mineral patent, which converted a claim to outright federal title, is in the GLO database.
• Deeds since county formation are kept by the County Clerk and Recorder in each of the 64 counties. FamilySearch has not microfilmed Colorado deeds, so you will work with the county office or its online index directly. Our how to trace a property's deed history walks through the grantor-grantee method.

Newspapers and city directories

The Colorado Historic Newspapers Collection (coloradohistoricnewspapers.org), a free service of the Colorado State Library, has more than 8 million digitized pages from over 1,000 Colorado titles published between 1859 and 2025, with new issues added regularly. It is the first stop for obituaries, mining-camp news, and legal notices, and you can filter by county, town, and date without an account. Check Chronicling America at the Library of Congress as well for titles that overlap or fill gaps.

For city directories, Denver Public Library's Special Collections holds the Denver run and directories for other Colorado towns, and the local public library is the next place to ask. Directories list occupation and employer as well as address, which helps separate two men of the same name in a mining town. See our guide to old city directories for search tactics.

Census, military, and statewide indexes

• Federal censuses cover Colorado from 1860, but that year the gold-rush settlements were enumerated as part of Kansas Territory (its Arapahoe County) and Nebraska Territory, so search both. Colorado Territory was not organized until 1861.
• The 1885 Colorado state census is the only state census; it is indexed with images on FamilySearch (free) and Ancestry. Mortality schedules, listing people who died in the year before the count, survive for 1860, 1870, 1880, and 1885.
• The State Archives' Colorado military records cover state-raised units; federal service and pension files are at the National Archives.
• The State Archives' marriage index and its online catalog search are the best statewide name indexes; the FamilySearch wiki page on Colorado Vital Records lists what has been filmed county by county.

Researching a house or building in Colorado

Colorado's State Historic Preservation Office is part of History Colorado, where it operates as the Office of Archaeology and Historic Preservation (OAHP). It administers the National Register of Historic Places program for the state and the Colorado State Register of Historic Properties, and its staff can tell you whether a building has been surveyed or listed. Denver, Boulder, Colorado Springs, and other cities also keep their own local landmark files.

For the building itself, trace the chain of title through the County Clerk and Recorder's grantor-grantee indexes, then add Sanborn fire insurance maps; the Library of Congress's free online Sanborn collection includes many Colorado towns, and Denver Public Library holds Denver sheets. Mining-town buildings often predate the first deed to the lot, because the townsite patent came years after the camp was built, so use newspapers to date construction. Our articles on when was my house built and researching an old building's history give the step-by-step method.

Working with Colorado's local societies

Most of Colorado's local societies are county-based and operate the county museum, which in mountain counties usually means summer hours and a winter closure; email before you drive over a pass. The front-range societies in Denver, Boulder, and Colorado Springs are open year-round and tend to have obituary indexes and photograph files. Railroad and mining history is spread across specialist museums such as the Colorado Railroad Museum in Golden, so if your ancestor worked for a railroad or a mine, ask the specialist museum as well as the county society. Cemetery questions go to the county society first; our how to find where someone is buried explains what to ask.

Additional Colorado History Resources

• Colorado State Archives - State and county records, pre-1908 vital registers, marriage index; Denver, by appointment
• CDPHE Vital Records Section - State birth certificates from 1910 and death certificates from 1900
• Colorado Historic Newspapers Collection - Free: 8 million+ pages, 1,000+ titles, 1859-2025, from the Colorado State Library
• History Colorado - Office of Archaeology and Historic Preservation - State Historic Preservation Office; National and State Register programs
• Denver Public Library Special Collections and Archives - Western History and Genealogy collections, digital collections, finding aids
• BLM General Land Office Records - Federal land patents and survey plats for Colorado homesteads and mineral claims
• FamilySearch Wiki: Colorado Vital Records - Dates, access rules, and county-by-county notes for Colorado vital records
• Chronicling America - Library of Congress historic newspaper archive

Frequently Asked Questions

When did Colorado start recording births and deaths?

Statewide registration began in 1908 and was not fully observed until the 1920s. Surviving earlier county registers (1876-1907) are at the Colorado State Archives in Denver, while the CDPHE Vital Records Section holds state death records from 1900 and birth records from 1910.

Where do I find Colorado homestead and mining claim records?

Search the BLM General Land Office Records for the federal patent, which gives the land office, date, and legal description. Claim location notices, mining deeds, and later property deeds are recorded by the County Clerk and Recorder in the county where the land lies.

Is there a free site for old Colorado newspapers?

Yes. The Colorado Historic Newspapers Collection, run by the Colorado State Library, has more than 8 million pages from over 1,000 titles dated 1859 to 2025, free with no account. Chronicling America at the Library of Congress is a second place to look.

Did Colorado take a state census?

Only once, in 1885. It is indexed with images on FamilySearch and Ancestry. For 1860, look for Colorado settlers under Kansas Territory (Arapahoe County) and Nebraska Territory, since Colorado Territory did not exist until 1861.