Nearing the Top, Ross Peak, Montana

Of Rocks: Conclusion

The underlying rock of the Puente Hills from the Bedford and Southern California Batholith basement to the Miocene and Pliocene sandstone, siltstones, and shale tells us a story about the …

Mountain Range, Western Montana

Third Rocks and Uplift

The third event recorded in the rock of the Puente Hills is the laying down of thick rock layers, which were subsequently uplifted. For over 10 million years in the …

Red Cliffs, Southern Wyoming

Second Rocks and Rotation

The second event recorded in the rocks of the Puente Hills began some 23 million years ago.  The trench system, which had for so long dominated the formation of Southern …