Devils Backbone Road Cut-Geology / Construction

This road cut exposes the upper Fayetteville Shale and overlying lower Pitkin Limestone, deposited in a shallow sea covering the southern Ozark region as the Mississippian Geological Period ended. As that sea regressed, the alternating Fayetteville black shale and fine-grained limestone layers forming the lower part of the exposure were succeeded by layers of lighter colored, shallower-water, coarse-grained Pitkin limestone exposed toward its top. Project engineer W.C. Johnston planned U.S. 65's relocation across Devils Backbone. D.B. Hill Contractor of Little Rock, under the direction of D.B. Hill Sr, completed construction in 1928, creating the original road cut. The company returned in 1972-74, under the direction of D.B. Hill Jr and the supervision of D.B. Hill III, to widen the highway and straighten the road cut to accommodate increased traffic.

Arkansas · United States