- Denver Public Library108,357
- Colorado State University. Libraries90,730
- University of Wyoming, American Heritage Center85,284
- History Colorado64,056
- University of Colorado Boulder University Libraries56,897
- Wyoming State Archives55,705
- Wyoming State Library48,882
- Aspen Historical Society41,929
- Fort Collins History Connection37,806
- Estes Park Museum25,924
- Pikes Peak Library District25,621
- Denver Museum of Nature and Science23,746
- University of Denver19,013
- Park County Archives, Wyoming14,860
- Colorado State Publications Library13,985
- Golden History Museum & Park11,937
- Eagle County Historical Society8,631
- Douglas County Libraries. Archives and Local History8,075
- Broomfield History Collections7,732
- The Brinton Museum6,856
- Carnegie Library for Local History, Boulder Public Library6,092
- Fort Caspar Museum5,946
- University of Northern Colorado5,937
- Campbell County Rockpile Museum5,548
- Louisville Historical Museum5,278
- City of Greeley Museums5,119
- Broomfield Veterans Museum4,762
- Aurora History Museum3,785
- Pueblo City-County Library District2,716
- Kit Carson County Archives2,390
- Colorado Snowsports Museum and Hall of Fame2,269
- CU Art Museum, University of Colorado Boulder1,509
- Park County Local History Digital Archive, Colorado1,427
- University of Wyoming1,415
- Leslie J. Savage Library1,352
- Fort Lewis College Foundation1,169
- Meeteetse Museums1,069
- Lakewood Heritage Center955
- USDA National Wildlife Research Center867
- Security Public Library752
- Museums of Western Colorado630
- Salida Regional Library627
- American Alpine Club591
- Pine River Library512
- Clear Creek County Library District500
- Tread of Pioneers Museum438
- Colorado Railroad Museum436
- Lafayette Miners Museum416
- Colorado State University-Pueblo. Library366
- Colorado Parks & Wildlife Digital Collection339
- City of Thornton Archives Digital Collection305
- Salida Museum Association304
- Gunnison County Library District283
- University of Wyoming Art Museum182
- University of Colorado Colorado Springs. Kraemer Family Library118
- Mesa County Libraries116
- Alamosa Public Library99
- Pitkin County Library79
- Vail Public Library78
- Front Range Community College37
- Ignacio Community Library31
- National Federation of the Blind of Colorado31
- Pines and Plains Libraries Digital Collection27
- Aspen Hall of Fame15
- Old Town Hot Springs14
- Eagle Valley Library District12
- Front Range Community College Larimer Campus9
- Black Citizens and Friends (Grand Junction, Colorado)7
- High Plains Library District7
- Stories of Colorado6
- Salida High School3
- Salida Fire Department2
- Fort Lewis College1
