W-16 Rapid City Route 16 section Starting in bzsc Gulch S of US16 just sw Rapid. 9.1-? sandstone, massive, fine to medium graded, tabular X lam weather brown. 5.5 Partly obscured, upper 2-3 feet Interbedded gray sandy clay stone & leusec & thin beds, SS. Some qyp in upper thins, which locally has much yellow stain 4.2 Claystone, gray, silty to sandy 24.7 Claystone, gray silty, loc. claysen siltstone, vary red, brown and yellow, upper 3.0 is stained yellow & orange, is lighter gray, weather white with yellow & orange stain. Fe specs pepper entire variegated zone, decrease in number downward. 27