Designed by Cecil Clyde Gideon, the self-taught superintendent of Custer State Park turned highway designer. He called them “spiral-jumpoffs”.
Composite of 3 images
August 20, 2007, 9:26 A.M. - Pentax K10D: ISO 100, 18mm focal length (27mm in 35mm format), 1/60 second, F4.5

from 