FOREST FORMATIONS AND FOREST TREES 



45 



Colorado forests in former geologic times.- — Professor T. D. A. 

 Cockerell, the authority on fossil plants of the Rocky Mountains, has 

 recorded a large number of species of trees which formerly grew at 

 Florissant and at other places in Colorado. The most easily accessible 

 of his papers are referred to in a footnote. 1 It appears that the forests 

 of Miocene times were made up of pines, cedars, willows, cottonwoods, 



Fig. 40. — Colorado Blue Struce 



birches, alders, oaks, hackberries, June berries, thornapples, locusts, 

 sumacs, maples, buckthorns and ashes, besides a number of eastern 



■ Cockerell, T. D. A., "Florissant; A Miocene Pompeii," Popular Science Monthly, Vol. LXXIV, 

 pp. 112-126, 1908. "Some Results of the Florissant Expedition of 1908," American Naturalist, Vol. XLII, 

 pp. 569-581, 1908. 



