Sincholagua and Ruminagui are the next two peaks, going southward, and then the unrivalled cone of Cotopaxi - the highest active volcano in the world - from whose summit smoke curls upward unceasingly.
Farther north the rainfall becomes heavier, the plateau is covered with vegetation, and a considerable number of small rivers flow westward through the Cordillera to the Pacific. The Eastern Cordillera, or Andes, forms the water-parting between the two systems. The largest of the eastward-flowing rivers is the Napo, which rises in the eastern defiles of Cotopaxi and Sincholagua - the principal source being the Rio del Valle, which traverses the Valle Vicioso.
For instance, in 1880 Whymper found permanent snow on Cotocachi at 14,500 ft., while near by Imbabura was bare to its summit (15,033 ft.); Antisana was permanently covered at 16,000 ft., and near by Sara-Urcu, which is drenched with rains and mists from the Amazon valley all the year round, at 14,000 ft.; Sincholagua had large beds of permanent snow at 15,300 ft., Cotopaxi was permanently covered at 15,500 ft.
The Napo rises on the flanks of the volcanoes of Antisana, Sincholagua and Cotopaxi.