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cessive summer rains and a gorgeous vegetation, which is desert 
until July, but at the first touch of the summer rains, starts into 
life and reaches its climax in September. [hese latter are tropi- — 
cal formations. e€ most important mountain formations are 
the Colorado formation, the Uinta, the Wasatch, the East Hum- 
boldt, the Malheur and the Sierra Nevada formations. The south- 
ern formations of most interest are the Kaibab, the Henry Moun- 
tains, Funeral Mountains, Panamint Mountains and White Moun- 
the Pinals, Catalinas, Huachucas, Santa Ritas, Floritas, Chirica- 
huas, and the Sierra Madres of Northern Mexico. 
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