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THE POPULAR SCIENCE MONTHLY
A Basin in the Ricardo Pliocene near Ricardo. (Photograph by C. L. Baker.)
| Geological Periods | Mammal Beds of the Mohave Area |
Recognized Formations of other Western Areas | |
| Pleistocene | Manix Beds | Rancho La Brea, California | |
| Pliocene | Upper | ||
| Middle | |||
| Lower | Ricardo Beds | Thousand Creek, Nevada Rattlesnake, Oregon | |
| Miocene | Upper | Barstow Beds | Cedar Mountain, Nevada |
| Middle | Mascall, Ore. and Virginia Valley, Nev. | ||
| Lower | Columbia Lava of Oregon | ||
Ricardo Pliocene at Ricardo. This is one of the most important fossil localities in the Ricardo formation. (Photograph by C. L. Baker.)
