I. 



STUDIES IN MESA AND FOOTHILL 

 VEGETATION, I 



Geology and Physiography of the Mesas near Boulder 

 Gideon S. Dodds 



2. Climatology of the Mesas near Boulder 



Francis Ramaley 



3. Distribution of Conifers on the Mesas 



W. W. ROBBINS AND GlDEON S. DODDS 



4. Distribution of Deciduous Trees and Shrubs on the Mesas 



W. W. Robbins 



I. Geology and Physiography of the Mesas 

 By Gideon S. Dodds 



In the following articles is given an account of some results of investi- 

 gations carried on by the writers during the seasons of 1906, 1907 and 

 1908. The area studied is the mesa region, at the foot of the Rocky 

 Mountains, just at the border of the plains. Observations have been 

 made of this area for some distance along the foothills north and south 

 of the city of Boulder, Colorado. A more detailed study has been made 

 of two mesas, Horse Mesa and Long Mesa, situated about two miles 

 south of Boulder, between Boulder Creek and Bear Canyon. (See 

 Plate I.) 



The object of these studies has been to determine the conditions 

 affecting plant distribution on the mesas. Studies have been made of 

 physical and meteorological conditions. Many of the plant formations 

 have been accurately mapped, and the physical characters of the different 

 habitats determined. In articles to be published later, other plant 

 formations will be described in relation to their habitats. 



General Appearance of the Mesas. — The following account of the 

 topography and structure of the mesas is taken verbatim from the 

 report of Fenneman on this area. 1 



1 Fenneman, N. M., "The Geology of the Boulder District, Colorado," U. S. G. S. Bull. 265, pp. 1-98 



