the location of the eastern edge of the sevier orogeny was determined by conglomerates largely made up of boulders that would have been shed from the eastern and steepest edge of the rising mountains. such conglomerates can be seen throughout utah in echo canyon, the red narrows in spanish fork canyon, and in leamington canyon near delta, utah. today sevier faults at the surface have been broken up and tilted steeply from their original gently dipping positions due to the extension of the basin and range faulting. the earliest thrusts of the sevier are located furthest west with each newer thrust cutting the older thrust. this pattern caused the older thrusts to ride on top of the younger thrusts as they moved eastward. the paris-willard thrust in utah was determined to be the oldest thrust in the series using this pattern. the youngest thrust is the hogback in wyoming.