46 RANGE INVESTIGATIONS IN ARIZONA. 



and White rivers and some are under contemplation by Messrs. Vail 

 & Wakefield in the Altar Valley near the Mexican Ijorder. 



THE PRAIRIE DOG. 



This little animal, Avhich has caused such devastation throughout the 

 plains region since its enemies have been killed 1)}^ the rancher and 

 his herdsmen, is without dou])t migrating into new territor}'. The 

 destruction wrought by it is more pronounced east and north of the 

 divide of the San Francisco and White mountains than anywhere else 

 in Arizona. Large areas have been completely overrun in the vicinity 

 of Flagstatf. In August a trip was taken through a very badly infested 

 area between Adamana and the White Mountains. PI. X, fiir. 2, shows 

 an infested area on the northern slope of the White Mountains, which 

 represents in some respects the greatest injur}^ that has been observed 

 in any region in the Territory. It is seldom that one can secure a 

 photographic representation of the work of the prairie dog, but here 

 the lime pebbles — or rather the lime-covered malpais rocks and peb- 

 bles — thrown out of the burrows furnish a sufficient contrast to the 

 black malpais rocks and bare ground to give a fairly good representa- 

 tion of the extent of the operations carried on by these animals. There 

 were no perennial grasses in the infested area, and but little vegeta- 

 tion of any kind. No area which has been visited within the Territory 

 is so badly overrun by these animals as that in the vicinity of the old 

 Twenty-four Kanch and southward to the base of these mountains. 



RANGE FEED. 



There is without doubt no part of the country where the character 

 of the native feed is so variable as it is in the Southwest; and this in 

 spite of the fact that the aggregate yield per acre is very low, and 

 that two crops are produced each year upon a large part of the range 

 country. We have a carrying capacity here varjang from one 

 animal to 40 or 50 acres to one animal to 100 acres, as compared with 

 one to 15 acres in portions of the Great Plains. At the same time, 

 the grasses, which are practically the only forage })lants in the latter 

 region, are much less numerous there than in the Southwest— much 

 less numerous in point of species. Some of the most important groups 

 of forage plants are discussed below. 



THE GRASSES. 



While it may be stated in general that of the forage production of 

 the Territory as a whole the grasses form the most important part, 

 yet the grass production is confined to the summer season of rain, and 

 consequently there is a large part of the year during which all stock 

 is obliged to subsist on other things. The grasses furnish good feed 

 from July to the 1st of January, but after that date, if the normal 



