Mining Bureau
- Gold and silver mining history in stereoviews and photographs.
- http://www.miningbureau.com/

High Stakes Preservation: Lost Colorado
- Photos of historical structures throughout the state. Includes history, construction and demolition dates, architect, and replacement structures where known.
- http://www.coloradohistory.org/HSP/LColoradopg1.html

Camp Hale
- Research project by the Metropolitan State College, documenting this military base founded by the Women’s Army Corp Detachment in the Pando Valley during World War II.
- http://www.mscd.edu/~history/camphale

State Emblems and Symbols
- Historical information and explanations for the state icons.
- http://www.colorado.gov/dpa/doit/archives/history/symbemb.htm

Colorado Firsts
- A chronological list of when and where events or ideas first occurred in Colorado.
- http://www.colorado.gov/dpa/doit/archives/arcfirst.html

State Government History
- Chronology describing the events that led up to the admittance of the 38th state of the Union.
- http://www.colorado.gov/dpa/doit/archives/arcgov.html

History Chronology
- Chronological description of the events of Colorado's pre-history, early history, and events up to World War II.
- http://www.colorado.gov/dpa/doit/archives/history/histchron.htm

Colorado State Archives
- The official repository for selected historical and contemporary records, and information generated by state and local governments.
- http://www.colorado.gov/dpa/doit/archives/

Postcard Collection
- Collection of photographic resources for visual representations of state tourism and daily life from 1900 to the present.
- http://www.colorado.gov/dpa/doit/archives/tour/post.htm

Colorado Digitization Program
- A collaborative initiative to provide access to the unique collections of Colorado's archives, historical societies, libraries, and museums.
- http://www.cdpheritage.org

Colorado Archaeological Network
- A group coordinating activities for the state Archaeological Society. Includes news and announcements, chapters, meeting schedule, and related links.
- http://www.coloradoarchaeology.org/

Putting Together Colorado Territory
- Traces the development of mail handling services in Colorado from the earliest period through the early Colorado Territory period.
- http://coloradoterritory.org

Colorado Historical Societies
- Locate address information (including web site links) to historical societies in each county within the state of Colorado.
- http://www.daddezio.com/society/hill/SH-CO-NDX.html

Stage Coaches - Photograph File
- Online collection of photographs of Colorado stage coaches from the Old Colorado City Historical Society archives.
- http://history.oldcolo.com/history/research/stagecoach1.html

American Eagles Scenic Overlook
- Information on a tour focusing on the gold rush history in Colorado.
- http://www.web-xpres.com/stcfgeagles.htm

Mining Photographs
- Online collection of photographs of Colorado mining from the Old Colorado City Historical Society archives.
- http://history.oldcolo.com/history/research/MINING1.html

HOP Ranch Cowboy Photographs
- Online collection of photographs of HOP Ranch cowboys from the Old Colorado City Historical Society archives.
- http://history.oldcolo.com/history/research/ranch1.html

Trolleys - Photograph File
- Online collection of photographs of Colorado Trolleys from the Old Colorado City Historical Society archives.
- http://history.oldcolo.com/history/research/trolley1.html

Census Data 1870 - 1920
- U.S. Census data, charted by year, covering the entire state of Colorado, by county.
- http://history.oldcolo.com/history/genhist/governmt/Census.html

State and City Business Directories
- An online collection of State and city business directories from the late 1800s and early 1900s from the Old Colorado City Historical Society.
- http://history.oldcolo.com/history/research/director/director.html