Clements, Edith S., Flowers of Mountain and Plain. H. W. Wilson Co., New York, 1926 (3d edition). More, Robert W., Colorado Evergreens. Denver Museum of Natural History, 1949. Guide to the conifers, with photographic illustrations. Nelson, Ruth Ashton, Plants of Rocky Mountain National Park. Government Printing Office, Washington, D.C., 1953. The basic reference on the wildflowers of the region. Pesman, M. Walter, Meet the Natives. Cooperative Printing Co., Denver, rev. ed., 1960. A guide to the flora of the region, with a color-key arrangement; useful anywhere in Colorado. Preston, Richard, North American Trees. Iowa State College Press, Ames, Iowa, 1948. An illustrated guide to all species of trees of North America. Roberts, Harold and Rhoda, Common Wildflowers of Colorado. Museum Pictorial No. 8, Denver Museum of Natural History, 1959. Roberts, Rhoda, and Ruth Nelson, Mountain Wildflowers of Colorado. Museum Pictorial No. 13, Denver Museum of Natural History, 1957. Fifty common mountain wildflowers described and illustrated.
Fishes
Beckman, William C., Guide to the Fishes of Colorado. Leaflet No. 11, Univ. of Colorado Museum, Boulder, 1952.
Geology
Pearl, Richard M., Nature as a Sculptor. Denver Museum of Natural History, 1956. A geological interpretation of western scenery, chiefly Colorado. Rocky Mountain Nature Association, Glaciers of Rocky Mountain National Park. Published in cooperation with National Park Service, U.S. Department of the Interior, 1959. Glacier story of Rocky Mountain National Park, past and present. U.S. Geological Survey, Denver Mountain Area Map. 1955. Covers most of Colorado’s Front Range and explains its geology. Wegemann, Carroll, A Guide to the Geology of Rocky Mountain National Park. Government Printing Office, Washington, D.C., 1955. Helpful road logs and the general geologic story of the park.
Mammals
Burt, W. H., and R. P. Grossenheider, Field Guide to the Mammals. Houghton Mifflin Co., Boston, 1956. A manual for the identification of all mammals north of Mexico. Rodeck, Hugo G., Guide to the Mammals of Colorado. University of Colorado, Boulder.
Mountain Climbing and Hiking
Henderson, Kenneth, Handbook of American Mountaineering. Houghton Mifflin Co., Boston, 1942. A pocket-size book, almost encyclopedic in scope, giving detailed information on mountain climbing and life on the trail. Nesbit, Paul, Longs Peak, Its Story and a Climbing Guide. Published by Paul W. Nesbit, Colorado Springs, Colo., 1959. Ormes, Robert M., Guide to the Colorado Mountains. Sage Books, Denver, 3d revised edition, 1955.