Colorado History

Established by Congress on February 28, 1861.

The Colorado area, first claimed by Spain in the16th century, and France in the 18th century. Spain traced its claim to the southwestern US to the 1540 Coronado expedition that explored much of New Mexico and Arizona. While he probably didn't reach present day Colorado, that didn't keep Spain from citing the trip as precedence for a claim to the Rio Grande and Colorado river basins.

The first Spanish settlements on the middle Rio Grande were in 1598. Spanish explorers had to have reached Colorado prior to 1694 since the written record from the Don Diego de Vargas 1694 trip into southern Colorado refers to already named landmarks that he passed.1

was acquired in part by the Louisiana Purchase (1803) and explored by U.S. Army officers Zebulon Pike (1806), Stephen Long (1819-20), and John Fremont (1842-43). Additional lands came from Mexico in 1848 as a result of the Mexican War, and from Texas in 1850.

Early Spanish explorers who came to Mexico heard the natives tell exciting tales of cities of gold and silver to the north. To find the precious metals many of these fortune hunters pressed northward, some of them coming into sections of the present New Mexico, Arizona, Utah, and Colorado. Some of these adventurers were the first white men to see the Grand Canyon of the Colorado, the Rio Grande Valley, and other sections of the Rocky Mountain Territory. Escalante, the Catholic priest who tried to find a shortcut from Santa Fe to the Pacific coast, came through there on his unsuccessful trip in the summer of 1776.

About fifty years later these sections swarmed with competing trappers and fur traders working for the various large fur companies of the eastern United States and Canada.

The real settlers of Colorado came about 1858, thus making the state the last to be occupied by permanent settlers. Many of the first comers were attracted by the discovery of gold and other metals. Not too successful in their fortune hunt, they turned to the land and the ranges for their livelihood.

The territory of Jefferson was voted by the residents in 1859 but was never recognized by congress. Thus some of the counties have organization dates and records prior to 28 February 1861 when the Territory of Colorado was recognized.

The 1860 census showed a population of about 33,000 men, and 1,500 women. This was taken when Colorado was still a part of Kansas.

The first territorial assembly created the first seventeen counties in September 1861. They were Arapahoe, Boulder, Clear Creek, Costilla, Douglas, El Paso, Fremont, Gilpin, Guadalupe (later named Conejos), Huerfano, Jefferson, Lake, Larimer, Park, Pueblo, Summit and Weld.

A few birth records before January 1907 may be obtained at the office of the county registrars, after January 1907 at the State Bureau of Vital Statistics in Denver. A few death records before January 1900 may be obtained from the respective county registrars. After these dates, from the State Bureau of Vital Statistics in Denver.

Marriage records were not generally recorded until after 1881, but some counties have marriage records as early as 1860, and are kept by the county clerks, as are probate matters, wills, etc. All land titles, deeds, mortgages, leases, etc are kept by the county recorder.

"Historical Atlas of Colorado", Thomas Noel, Paul Mahoney and Richard Stevens, Univ of Oklahoma Press, 1994.

The Colorado Archives: Colorado State Government Colorful Colorado History Page

The Original Territorial Counties and Their County Seats in 1861


  • Arapahoe
  • Boulder
  • Clear Creek
  • Costilla
  • Douglas
  • El Paso
  • Fremont
  • Gilpin
  • Guadaloupe(later Conejos)
  • Huerfano
  • Jefferson
  • Lake
  • Larimer
  • Park
  • Pueblo
  • Summit
  • Weld

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County Seat

  • Denver
  • Boulder
  • Idaho
  • San Miguel
  • Franktown
  • Colorado City
  • Canon City
  • Central City
  • Guadaloupe
  • Autobees
  • Golden City
  • Oro City
  • La Porte
  • Tarryall City
  • Pueblo
  • Parkville
  • St. Vrain