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Sierra Club Bulletin, 



from a plain, over 8000 feet high, and quite as level as 

 the valley of Mexico. As the sides slope gradually, par- 

 ticularly near the base, it obviously covers a large terri- 

 tory. 



We started from Calimaya shortly after daylight, and, 

 as the date was the first of November, the air was frosty. 

 We left the town behind us and, gradually ascended. The 

 sun came out and the air grew warm. At eight o'clock 

 we stopped for a cup of fresh milk at the hut of an Indian 

 cattlehcrd. From here the trail grew steeper, but con- 

 tinued without much zigzagging up to the timber line at 

 about 13,000 feet. Here it turned to the left and went 

 across the mountain, ascending with a regular grade to 

 a low gap on the northwest side, which gave entrance to 

 the crater. 



The floor of the crater is a hundred feet below this gap. 

 In the middle a mound of lava rises to a height of 500 

 feet. On the west side of this mound are two small, 

 shallow lakes and on the south side lies a larger one, half a 

 mile in length and very deep in the middle. The water in 

 the lakes is clear and fresh, but I saw no evidences of life 

 in it. Bunch-grass grows sparsely on the crater floor, but 

 there are no trees. The highest point, El Pico del Aguila, 

 is on the southwest side, 1500 feet above the level of the 

 lakes. The rim of the crater slopes down sharply on the 

 west side of the peak, but maintains a rather even level 

 on the south side, with an inside slope so steep that it is 

 surprising that the volcanic ash with which it is covered 

 does not slip down. This ash lies in vertical streaks of 

 brick-red, lavender-gray, and yellow. El Pico del Aguila 

 itself is rocky, and offers the only approach to rock 

 climbing to be found on any of the mountains under 

 consideration, if ascended by their easiest routes. Al- 

 though snow often fills the crater and comes well down 

 on the sides of the mountain, at this time there were only 

 some vertical streaks on the inside of the crater wall, 

 where altitude and northerly exposure tend to conserve it. 



In ascending to the summit, we rode along the rim to a 



