[12] With the recognition of the vast extent of the group, the group has been divided into formations by region, with the original Point Lookout Sandstone, Menefee Formation, and Cliff House Sandstone being restricted largely to the San Juan Basin and the Madrid, New Mexico area.

The group is a single regression-transgression sequence in its type location in the San Juan Basin, dividing the older marine Mancos Shale and younger Lewis Shale deposited in the Western Interior Seaway.

In other locations, such as along the Book Cliffs, the picture is more complicated, with multiple regression-transgression sequences from tectonic activity along the Sevier mountain front.

[13] In the Cody area, the group is a simple regression sequence and remains at formation rank.

Here the group is described as interbedded light gray sandstone and gray shale in the upper part; massive, light-buff, ledge-forming sandstone containing thin lenticular coal beds in the lower part.