| Snyder Hill, a block of the Concha and Rain Valley formations in the Tucson Mountains | |
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| The Rain Valley Formation can be decerned from the Concha Limestone by the Presents of siltstone and mudstone that is not found in the Concha Limestone below. Move your mouse over the picture above to see the divide more clearly. The Rain Valley Formation rests conformably on the Concha limestone, the different rocks representing different depositional environments. The Rain Valley Formation is largely Kaibab equivalent and represents a marine deposition as well as the youngest Permian/Paleozoic rocks in the state. The Kabab Limestone caps the Mogollon Rim and the Grand Canyon in Northern Arizona |
*From the Southern Arizona Guidebook III