In most cases the activities of fire and ice left our surfaces broken, jagged, rough; no sooner did these forces die down than the waters of running streams, and still later the winds, took up the work of polishing. The results of these slower but not less effective forces include some amazing freaks, marvels comparable with those of almost any part of the world.

The great lava-walled gorges of the Salmon and the Snake are the work of streams of water operating through almost endless ages.

Along the sides of the canyon of Salmon Falls Creek in Twin Falls County the lava has been worn by the elements into strange and freakish monuments, pinnacles and towers, from which the crossing and community have received the name “Castleford”. High up on a ledge in the wall of the canyon is one of the most remarkable balanced rocks in the world, comparing favorably with the more widely advertised stone in Colorado’s Garden of the Gods. The Idaho Balanced Rock is a massive irregular toad-stool-shaped stone 38 feet high, 27 feet across the top, connected to its base by a pedestal only a few inches thick.




Sources:
"Idaho: The Place and Its People" by Bryon Defenbach
"History of Idaho" by James H. Hawley