Tafoni Boulder

Quick Facts

MANAGED BY:

Idaho Department of Parks and Recreation

Amenities

1 listed

Scenic View/Photo Spot

Immediately to the north of Three-Pool is a boulder exhibiting a dramatic example of honeycomb, cavernous, or tafoni weathering.

Tafoni occurs when cavernous weathering creates small hollows on joint surfaces. These hollows gradually enlarge through the creation of a sheltered micro-climate that facilitates the accumulation of salt. Salt is a corrosive agent that expands when dry and breaks apart the granitic minerals. While salt minerals do occur naturally in the granite, they are more likely transported by wind and rain from the playas of the Great Salt Lake basin, only 30 miles south of here.  

As salt eats away the interior, the case-hardened outer layer or shell erodes much slower, creating delicate arches, windows, and honeycombs.