Information requests
1	Improving content on US states
Introduction
2	Introduction to photography in Colorado
Photographers
3	Timothy O'Sullivan: Explorations and Surveys West of the 100th Meridian (1871-1874)
4	William Bell: U.S. War Dept., Corps of Engineers; Geographical Explorations and Surveys West of 100th Meridian, Expedition of 1872; Lieut. Geo. M. Wheeler, commanding. / Colorado River Series [Stereoviews]
5	Duhem & Bro.: Beauties of the Rocky Mountains. (1869-1879) [Series]
Significant locations
6	Colorado: Mountain of the Holy Cross
7	Colorado: Garden of the Gods
8	Bone Field on Talbot Hill, 10 miles from Canon City, Colo.
9	A Rephotographic Survey of the American West: Mountain of the Holy Cross

Robert Adams (1937-), C.F. Allen, C.F. Alter, Bagley, S.S. Baldwin, Barker & Mellen, T.E. Barnhouse, Barnhouse & Wheeler, William L. Bates, Bates & Nye, Bee Hive Photograph Studio, George Bertrand, Bohm, J.A. Boston, Boston & Ziegler, Eugene Brant, Alfred & M.L. Brisbois, T.B. Brooks, H. Brown, Harman Brown, J.P. Carter, Chain & Hardy, W.G. Chamberlain, D.B. Chase, Chase & Lewis , Chase & Wolcott, B.L. Childers, W.D. Churchill, C.H. Clark, J. Collier, Robert Collier, C.H. Collings, M. Collins, Colorado Springs Co., Colorado Stereograph Co., Colorado View Co., J.J. Cornish, Cunningham & Co., Robert M. Davis, Frank E. Dean, A.W. Dennis, A.E. Dickerman, Dickerson, A.C. Dickerson, Duhem & Bro., R.F. Elliott, Charles E. Emery, C.W. Erdlen, Henry Faul, Mrs. H. Galbreaith, Galbreaith & Co., Galbreaith, Harvey & Lyle, William M. Gatch, Gilbert, Charles L. Gillingham, Chas. Goodman, R.W. Groves, Byron H. Gurnsey, Gurnsey & Brandt, George H. Hall, Harvey, B.A. Hawkins, E.B. Headley, E.B. Headley, Headley & Morgan, H. Hemenway, John K. Hillers (1843-1925), T. Hine, W.E. Hook, William Henry Jackson (1843-1942), J. Martin Kirby, C.D. Kirkland, Geo. W. Kirkland, Kirkland Bros., Ira D. Kneeland, Harry C. Knight, Kuhn & Wheeler, Frank Kuykendall, Kuykendall & Whitney, L.H.V., Standish D. Lawder, W.H. Lawrence & Co., W.O. Luke, Luke & Wheeler, J.C. Macurdy, J.C. Macurdy, Dr. Miles Markley, A. Martin, Martin & Mills, Martin & Peers, Mrs. G.H. Masters, Mrs. M.A. Maxwell, Albert S. McKenney, McKenny , McKirrahn & Whitter, Lachlan McLean, Martin W. Mealey, George E. Mellen, Mexican & Indian Curio Co., T.C. Miller, Miller & Nutt, David Morison, E.G. Morrison, Mulhall & Alexander, Charles A. Nast, Nast & Martin, Nast Bros., Nelson Studio, George O. Nevins, F.A. Nims, Timothy H. O'Sullivan (1840-1882), L.K. Oldroyd, Perry & Bohm, C.A. Pollen, C.E. Purcell, William H. Reed, Reed & McKenney, Rice's News Room, J.R. Riddle, A.E. Rinehart, Robinson & Shipler, Seton Rochwite, W. Ira Rudy, Rudy & Clinton, Russell & Luke, Schert & Taylor, Shaffner & Milner, J.W. Shipler, Shipler & Williamson, Snider, Pont Soderberg, Stone & Co., Frank D. Storm, H.W. Stormer, Swan Bros., Chalmers W. Talbot, N.H. Talbot, Talbot & Nelson, Ed Tangen, Glen Thrush, J. Thurlow (1831-1878), George D. Wakely, Charles Weitfle (1836-1921), C.H. Wells, Wheeler, W.A. White, W.H. Whitney, Edwin A. Wilder, Williams & Bro., Williams & McDonald, J.G. Wilson, G.W. Wright, Yelton & Wispa