Colorado research guide

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Year range
1840 - 1990



What is now Colorado was controlled by many jurisdictions, and thus, the records you seek may not be where you expect them. Colorado was ruled by Mexico, Spain, France and the United States. In colonial times, Spain and France alternated control of the northeastern region until France sold it to the US in 1803. Mexico controlled the area southwest of the Arkansas River until the US acquired it in 1848.

Mexico was actively issuing land grants and encouraging colonists in the Colorado region into the 1840’s. Hispanic settlers continued to migrate and made the first permanent settlement at St. Luis in 1951. The US divided the region between Missouri, Utah, Kansas, Nebraska, and New Mexico territories. Territorial records exist for the Kansas, Nebraska, New Mexico, and Utah, but not for the Missouri region. Gold Miners organized Arapahoe County in the Kansas Territory in 1858. Congress created the Colorado Territory in 1861. Colorado became a state in 1876. Over 400,000 people lived in Colorado by 1890. Colorado and Its People: A Narrative and Topical History of the Centennial.

US Settlers immigrated first because of the gold rushes of 1858 and 1859 and secondly because of the railroad which was connected in 1870. In 1860, settlers generally came from Ohio, Illinois, New York, Missouri, and Indiana, in that order. After the civil war, American settlers generally came from Missouri, Kansas, Nebraska, and Iowa. However after 1880, about 20% of the settlers were not from the US. The state had three official languages: English, Spanish, and German.


Census records are helpful because they often list family members and relationships, origin information and occupational information that is not easily found in other sources.

The 1860 Territorial Census was taken before the Colorado territory was organized. Thus, Colorado residents were enumerated by several different territorial censuses.

  • Utah portion contained Leadville but was not enumerated.
  • Nebraska Territorical Census contained Altoona City, Boulder City, Boulder Creek Settlement, Gold Hill Settlement, Miraville City, and Platte River Settlement and is enumerated as “unorganized territory.” Ted and Carol Miller transcribed this Colorado portion.
  • Denver City partially enumerated in the Nebraska portion and partially in the Kansas portion. The Kansas portion is enumerated as “Arapahoe County,” The index is on microfiche at the FHL and can be found in search 7a on AIS.
  • The Southestern part of Colorado was enumerated with the New Mexico Territorical census in “Taos” and “Mora” Counties.
  • Utah Territory took in the rest of what would be Colorado. It was considered unsettled and was not enumerated.

There is a card index, with separate indexes for the New Mexico and Nebraska portions at the Colorado Historical Society.

There was a state enumeration taken in 1866 for the Northeastern counties. It is available from the Colorado State Archives.

The Censuses of 1870, 1880, a special Federal 1885 census, 1900, 1910, 1920, and 1930 are available at various places. The 1890 Census was destroyed. Colorado Historical Society has microfilmed and indexed the schedules for 1860, 1870 and the 1880 censuses. Microfilmed census schedules together with soundex indexes are available from the NARA, Norlin Library, and FHL. Denver Public Library Western History Department houses microfilmed copies of most of the censuses with soundex and printed indexes.

Mortality Schedules

A mortality schedule is a list of deaths for the year before the census was taken. The 1860, 1870, 1880, and 1885 censuses include mortality schedules. Indexes for these schedules are available at the FHL.

Vital Records

Initially, vital records were kept by churches and county clerks. Some counties have records as far back as 1860. Most of the older records have been moved to the Colorado State Archives.

Although the state required registration in 1876. A few counties complied and the records would be kept in the county court house or have been transferred to the Colorado State Archives. Colorado did not begin statewide registration until 1907. However, citizens didn’t take it seriously until sometime in the 1920s. Early records may be stored at the local church or county clerk, or may have been transferred to the Colorado State Archives. To navigate these records, see Guide to vital statistics records in Colorado. Volume 1 is concerned with public archives and volume 2 is concerned with church held records. This set is available at the Colorado Historical Society Library, FHL, and elsewhere. Birth and Death records, if available, may also be requested from the CDPHE.

Marriage records were kept with the County Courthouse from the date of their incorporation. Many earlier records have been moved to the Colorado State Archives. CDPHE has marriage indexes from 1900-1939 and 1975 through the present. It also has certain records from 20 out of 63 counties. An index for marriages, 1975 through present, is also available online through the Denver Public Library Western History Department and on FHL films beginning with Source:Statewide marriage index, 1900-1939, 1975-1992 . Some early marriage records have been extracted by the Colorado Genealogist. Marriages of Arapahoe County has the earliest records for that area.

Divorces are recorded with the county clerk; indexes for divorces 1900-1939 and 1968 through the present are available through CDPHE.

Church Records

Early vital records were often kept with the local church. See, Guide to Vital Records, referenced in the Vital Records section. You may get lucky and find what you want in this index. However, for many churches, you’ll need to know the particular church your ancestor attended. Further, records concerning marriages, deaths, and births are kept only at that particular church house and not by any archive. Frequently, church archives only keep records concerning their clergy, they do not keep records about parishioners.

For Catholic records contact the Archdiocese of Denver for northern records, the Archdiocese of Colorado Springs for east-central records, and the Archdiocese of Pueblo for southern records. FHL also has some church histories.

Cemetery Records

Cemetery records are usually a good source of birth and death information. Kay Merrill's book Colorado Cemetery Directory examines and lists every known cemetery in Colorado by county. It will tell you the location, condition of the cemetery and if records are available. It is available at the Denver Public Library. Thirty three small cemetery have been transcribed by Lela O. McQueary and Kay Merrill in Colorado Cemetery Inscriptions. Additionally you can search many Colorado cemeteries at You will need to write to the cemetery for copies of the actual records.

Military cemetery records are transcribed separately. Records for Fort Logan National Cemetery and Fort Lyon National Cemetery have been indexed and may be searched on line. However, if you need a cause of death or a copy of the records, you will need to write the Adjutant General.


Obituaries are secondary sources, often reported by poorly informed or stressed family members. However, obituaries are a good source of basic information. Denver Public Library - Western History Collection has a card index for the Rocky Mountain News (1865-1885) and an obituary index for the Denver Post and Rocky Mountain News (1939-present). Denver Obituary Index has many Denver obituaries indexed on-line. See also, Donald E.Oehlerrts,comp., Guide to Colorado Newspapers, 1859-1963 and A Comprehensive Guide to the Location of Published and Unpublished Newspaper Indexes in Colorado Repositories.

Land and Property Records

Sometimes placing an ancestor in a particular area can be very helpful. You may not know the birth date or death date, but placing him or her will help you find other records. For instance, if you can place a grandfather in a particular area and era, you would then know what church records to search in for vital information.

Spanish and Mexican were the first land records kept:

Many of the records of the Spanish and Mexican land grants are located in the Denver Public Library - Western History Collection.

The US agreed to honor the Mexican land grants when it acquired the southwest portion of Colorado. These were recorded by the US Surveyor General 1855-1890. However before 1862, some Colorado claims were processed by the Bureau of Land Management, New Mexico office.

Most of Colorado’s land remained unclaimed in 1861. In 1962, congress passed the Homestead Act. The first land office was opened in 1863 around Denver. Land Offices were subsequently opened in Cental City, Del Norte, Denver, Durango, Glenwood Springs, Gunnison, Hugo, Lamar, Leadville, Montrose, Pueblo, and Sterling. Federal land patents are archived at NARA in Washington, D.C. (You will write or visit.) and at BLM.

Patents, Township Plats and copies of Tract Books are at the Bureau of Land Management, Colorado State Office. Land that was transferred between private parties is recorded by the local County Clerk. You will have to write the local County Clerk to obtain these records.

Military Records

Military records often contain lots of helpful information. They may list nationality, birth place and date, next of kin, address, occupation, age, even a physical description. For civil war (1861-1865) soldiers check the Index to Compiled Service Records of Volunteer Union Soldiers. The union civil war service and pension records are available at NARA. For the union civil war roster see Colorado Volunteer in the Civil War: The New Mexico Campaign in 1862. For 1798-1914 check the Registers of enlistments in the United States Army, 1798-1914; these may give name, rank, company, regiment, description, age, occupation and birthplace. For 1917-1918 (World War I) you can check draft registration Cards for any man aged 18-45 during this period. Not all registered men served. Some useful information may be gleaned from state muster rolls and federal pension records. Old War Pension Index, Indian Wars Pension Index, 1892-1926, Indian Wars Pension Index, 1817-1898, and Remarried Widows Index.

Immigration and Naturalization

Prior to 1906 naturalization records were kept either at the local or US District Court. Early records and territorial records may be held by the Colorado Archives. After 1906, the federal district courts had jurisdiction. For federal districts of Montrose, Pueblo, Del Norte and Denver 1877-1952 check at NARA, local INS office or FHL films. There is an index to these naturalization at the Denver District Court. Some abstracts of naturalization records were indexed by the Colorado Historical Society in their journal The Colorado Genealogist, you can check their subject index.

Newspapers and Periodicals

Old newspapers and periodicals can help you know your ancestor. Why did people leave everything behind to become pioneers? Why did they stay in Colorado? What was life really like for them? Even if an article is not about your particular ancestor, it may help you understand what it was like way back then and even give you a lead to finding information about your ancestor. Denver Public Library—World History Department and Colorado Historical Society have good collections of newspapers and an index of obituaries. If you are from Pinon county, you can also check the Pinon Whispers Cemetery Records See also, Donald E. Oehlerts, Guide to Colorado Newspapers, 1859-1963 (Denver: Bibliographical Center for Research, 1964]]. You may also wish to check Pinon Whispers, Boulder Genealogical Society Quarterly, and Colorado Genealogist.

Probate Records

Probate records besides recording wills (refer to family members’ names and relationships) also record affidavits, case files, affidavits, letters, calendars, dockets, claims, accounts and judgments. Any of these may help you understand some of the major events and relationships in your ancestor’s life. These documents are kept at the local court house. Check in Ella Ruland MacDougall's Abstracts of Early Probate Records.

Bible Records

Many settlers kept recorded vital information in the cover pages of the family bible. These document s are of great value to the genealogist. You may find the names and information about family members not recorded anywhere else, such as those of children that died in infancy and spouses of siblings. Colorado citizens didn’t really take civil records seriously until the 1920’s. Even if your ancestors are from a jurisdiction that kept earlier records, that family may not complied. The family bible may be the only record there is for generations. The DAR has made a collection of Family Bible records which is partially indexed by E. Kay Kirkham in An Index to Some of the Bibles and Family Records of the United States. Other family records may be availible from the DAR ancestor index.


You may find your ancestor or related persons in biographical collections. Reading a few biographies can also help you understand what life was like, as well as the interests, concerns and ideas of the times. Colorado Historical Society has a great 5 volume vertical file of biographies and the Bromwell Index. The Bromwell Index is an alphabetical list of prominent Colorado residents up to 1933. You may also try three other biographical enclopedias Stone's History of Colorado and Portrait and Biographical Record of the State of Colorado,and Ancestry's book of Denver biography's. You can enter "colorado history" in WeRelate's source search box and find another 1700 plus relevant sources.

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