Ruth Sims, Albuquerque, New Mexico, to Laura Gilpin. November 24, 1941.

Barbara Cooper, Laramie, Wyoming, to Laura Gilpin. January 7, 1942.

Laura Gilpin, Colorado Springs, Colorado, to Dr. Fisher. March 16, 1942.

Laura Gilpin, Colorado Springs, Colorado, to William A. Kittredge, Lakeside Press. February 17, 1942.

Laura Gilpin, Colorado Springs, Colorado, to Albert G. Simms. November 18, 1941.

Spud Johnson, Laughing Horse Bookstall, Taos, New Mexico, to Laura Gilpin. August 7, 1941.

Laura Gilpin, Santa Fe, New Mexico, to Cady L. Daniels. October 17, 1945.

Wichita Salon of Photography, Wichita, Kansas, to Laura Gilpin. February 26, 1945.

Brenda Putnam, New York, New York, to Laura Gilpin. September 17, 1945.

Victor W. Hungerford, Sherwin and Hungerford, Attorneys at Law, Colorado Springs, Colorado, to Laura Gilpin. October 6, 1943.

Laura Gilpin, Colorado Springs, Colorado, to Mr. Walter Loban, Northwestern University. March 20, 1941.

Lillian Gish, New York, New York, to Laura Gilpin. May 2, 1942.

Charlton Ogburn, Oakton, Virginia, to Eliot Porter. May 28, 1976.

"National Audubon Society: Four Programs to Conserve Critical Habitat." n.d.

"The Peninsula" by Louise Dickinson Rich. 1958.

"The National Parks: What They Mean To You And Me" by Freeman Tilden. 1957.

Introduction to "Exploring Our National Parks and Monuments" by Devereux Butcher. 1956.

Journal XIV-41. June 6, 1969-August 12, 1972.

"Porter Catalog," Color Three Associates. November 5, 1987.

Hiag Akmajian, Carmel Highlands, California, to Eliot Porter. January 21, 1980.