Devil's Post Pile National Monument, Basalt Columns
Additional Details:
| This National Monument is one of the smallest, a rectangular area 2.5 miles by half-a-mile wide, extending along both sides of the middle fork of the San Joaquin River. The forty foot cliff of columnar basalt is composed of columns that are nearly perfect prisms. Two feet in diameter and almost vertical, they fit together like cells of a honeycomb. Most of the prisms are pentagonal, though some are four or six sided. |
