The boundary between the Colorado orogeny and the Wyoming craton is the Cheyenne belt, a 5-km-wide mylonitic shear zone that verges northward.
Adjacent to the Cheyenne belt, and extending across a width of at least 150 km to the south, foliation and upright folds predominantly trend westward.
In the northern Front Range sector of this region, geologic mapping demonstrated three generations of northwest-trending folds that pre-date the ~1.4 Ga shear zones.
These structural fabrics indicate shortening in a north-south direction and can be explained by collision, subsequent subduction, and continued convergence along the Cheyenne belt.
Farther south, more distant from the Cheyenne belt, fold patterns differ materially from those in the northernmost part of the Colorado orogeny.