Incahuasi Central Volcanic Zone of the Andes together with about 110 other Quaternary volcanoes, and lies in the southern sector of the volcanic zone; other volcanic zones in the Andes are the Northern Volcanic Zone, the Southern Volcanic Zone and the Austral Volcanic Zone. The history of volcanic activity is poorly known for most of these volcanoes owing to the lack of dating; only a few historical eruptions have been recorded, such as an eruption at Ojos del Salado in 1993. Incahuasi is located northeast of Ojos del Salado, the highest volcano in the world. Both volcanoes are found at the
Spanish Peaks (Montana) Spanish Peaks (Montana) The Spanish Peaks, avg el. , is a mountain range between Bozeman, Montana and Ennis, Montana in Gallatin and Madison County, Montana. It is a sub-range of the much larger Madison Range, itself a sub-range of the Rocky Mountains. The hydrological divide of the range serves as the border between Gallatin and Madison County, Montana. The Spanish Peaks are made up of 1.6 billion year-old gneiss, making them the oldest peaks in the Madison Range, predating the rest of the range by 50-60 million years. Gallatin Peak, el. 11,015 ft., is the highest peak in the group.