The nature preserve is located in a alpine glacially carved valley in the Central Andes immediately east of Santiago, just 25 km east on Camino a Farellones.   The highest peak, at the upper end of the valley, is El Altar at 5,222 meters above mean sea level (msl).   The stream (Yerba Loca) that flows through alpine valley originates at 3,900 m, below another peak, La Paloma.
Yerba Loca Nature Santuary ranges in elevation from 900 to 5,500 m msl.
The vegetation at Yerba Loca is an alpine scrub, dominated by chaparral-like low shrubs and a rich assemblage of perennial herbs.   The santuary is named after an herb common in the area.
All photographs copyrighted by David L. Magney 2004