Time-parallel limestone beds of the well-known Kansas section have been traced westward in an attempt to determine their total geographic extent, their origin, and their utility in precise regional correlation. The entire sequence of marker beds extends from Canon City, Colorado, to Springer, New Mexico. Certain groups of these markers are traceable southward to White Oaks, New Mexico, northward to the Black Hills, and westward to the northern San Juan basin. The most widespread limestone beds were deposited across areas no smaller than 388,000 sq km (150,000 sq mi). Individual beds are identified positively by position in sequence, relation to adjacent bentonite seams, lithology, and fossils. Each bed is thoroughly bioturbated, and the thickness, fossil content, and fiel characteristics are remarkably uniform for great distances. Dominant mineralogy is calcite; quartz and pyrite are the only consistent accessory minerals. The limestones are micritic to microsparitic wackestones and, uncommonly, packstones. Principal allochems are planktonic forams, inoceramid bivalve fragments and prisms, calcispheres, and oyster fragments. Fecal pellets are scarce west of the Rocky Mountain front but common in Great Plains sections. Limestone bed contacts are mostly gradational with adjacent shaly strata, and evidence for hardgrounds is lacking.

Limestone beds of the Bridge Creek Member reflect offshore shelf deposition during the late Cenomanian-early Turonian transgressional maximum of the Western Interior sea. Relative proportions of pelagic versus benthonic allochems confirm that limestone beds represent slow deposition caused by reduced detrital influx. Deposition occurred on a nearly planar surface, with local highs marked by areas of condensed sequences.

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