VEGETATION OF DESERT MOUNTAINS 



299 



a marginal growth of Yucca, The large triangular area which 

 receives this natural and continuous sub-irrigation from the 

 waters of Grant and Goudy canons has been the seat of successful 

 agricultural operations from the earliest settlement of Arizona. 

 The extent of pine forest in the Pinaleno Mountains is not 

 so great as might be expected from the size and altitude of the 

 range, owing to the extremely steep and rocky character of the 

 slopes that lie at favorable altitudes for the pines. The total 

 area of forest is about 56 square miles, if we comprise the encinal 

 and brushland that lies above the normal lower limits for the 



Fig. 4. A park on the main ridge of the Pinaleno Mountains at 9200 feet sur- 

 rounded by forest of Pinus ponderosa. The park is chiefly occupied by Dugaldea 

 hoopesii. 



pine. The total area of the mountain lying above 8000 feet is 

 slightly over 35 square miles, and this is almost completely 

 covered with forest. 7 Out of the 21 square miles of forest or 

 potential forest below 8000 feet it is doubtful if the pines occupy 

 more than 8 to 10 square miles, whereas they occupy scarcely 

 more than this much of the heavily forested area above 8000 

 feet, where other trees are dominant. 



7 I am indebted to Mr. T. T. Swift, Supervisor of the Crook National Forest 

 for the loan of maps of the Pinaleno Mountains from which these computations 

 of area were made. 



