miles north of Ouray, Colorado. They found that nonfossiliferous red beds provisionally assigned to the Dolores Formation were separated from overlying fossiliferous Triassic beds by a significant angular unconformity. The lower beds were tentatively identified as Permian beds, and were removed from the Dolores Formation to the newly designated Cutler Formation. Baker and Reeside revised Cross and Howe's work in 1929, tracing the Cutler across the Colorado Plateau and dividing the formation into the Halgaito Tongue, Cedar Mesa Sandstone Member, Organ Rock Tongue, and White Rim Sandstone Member. They also confirmed Cross and Howe's dating of the formation to the Permian. The Cutler was traced through the Jemez Mountains and found to be laterally equivalent to the Abo Formation by Wood and Northrop in 1946. In 1958, Wengerd and Matheny raised the formation to group rank. References External links Geologic formations of Arizona Geologic formations of Colorado Geologic formations of Utah Permian Arizona Permian Colorado Permian formations of New Mexico Permian geology of Utah Cisuralian Series of North America Sandstone formations of the United States Fluvial deposits Lacustrine deposits Permian northern paleotropical deposits Paleontology in Colorado Paleontology in New Mexico Paleontology in Utah