An exhaustive field study of the Cambrian stratigraphy of the northern Wasatch region indicates that in addition to the Blacksmith Fork section there are two complete and better exposed middle and upper sections. Several other good exposures of the lower Middle Cambrian section have been studied in detail. The Spence shale is found to be a member low in the Langston, not the basal member of the Ute. Relative ages of the Spence shale and Ptarmigania faunas have been determined. Other Cambrian faunal zones have been discovered and are discussed. Paleontologic evidence suggests that the Nounan formation is of Upper Cambrian (Cedaria) age. Laboratory and field evidence indicates the probable Lower Cambrian age of the Brigham formation.