1S90.] Mearns, Arizona Mountain Birds AC 



Dr. Merriam's* records from the rice fields of South Carolina and 

 Georgia, which the birds frequent until May 29, a date at which 

 we generally consider the migration to be nearly completed and 

 when their earlier comrades are already well established in their 

 summer housekeeping. 



OBSERVATIONS ON THE AVIFAUNA OF 

 PORTIONS OF ARIZONA. 



BY EDGAR A. MEARNS, M. D. 



These observations are confined to the alpine regions of Ari- 

 zona, which I explored during a residence of over four years in 

 the Territory. 



The mountain system of Arizona is a continuation of both the 

 Rocky Mountain chain and the Sierra Nevada. In 43 30', north 

 latitude, the Wind River range of the Rocky Mountains divides 

 about the remote sources of the Great Colorado River. One 

 branch trends southward, and passing around the sources of the 

 Platte, the Arkansas, and the Rio Grande, is merged in the Guada- 

 loupe Mountains, and at last loses itself in the great prairie plains 

 of the southwest. The other branch, turning to the west and 

 south forms the Wasatch range, the eastern rim of the Utah Basin, 

 and, widening out to the level of the great plateau, reaches the 

 canon of the Colorado, near ii2°of longitude. 



A branch of the Sierra Nevada deflects from that range east of 

 Owens River, and, with a general trend to the southeast, passes 

 by the head of the Virgin River, becomes merged in the plateau, 

 and unites with the Wasatch at the Grand Canon of the Colorado. 

 These united i - anges form the mountain system of Arizona, and 

 south of the Colorado River break up into parallel ridges, isolated 

 groups, detached spurs and peaks, which are again united in one 

 massive- chain in the Mother of Mountains in northern Mexico. 



The San Francisco peak, volcanic in its origin, may be 

 considered the apex of the Arizona mountain plateau, and the 



*Dept. of Agriculture, 1886. Report of the Ornithologist and Mammalogist, pp. 

 248-249. 



