"Deformation of shale by porphyry, Burlington Railroad, east of Whitetail Gulch." -Walcott, 1901

Shale Deformation

"Deformation of shale by porphyry, Burlington Railroad, east of Whitetail Gulch." -Walcott, 1901

"Conduit of Tilford laccolith, showing porphyry (P) breaking across limestone (L)." -Walcott, 1901

Laccolith

"Conduit of Tilford laccolith, showing porphyry (P) breaking across limestone (L)." -Walcott, 1901