- The Temecula Trough
- After the Santa Rosa Basalt erupted 8-10 million years ago, the San Andreas Fault formed, the Sierra Nevada rose, and the Santa Ana Mountains were created, forming our present-day landscape.
- The Santa Rosa Basalt kept the area dead flat in places where it still exists, and fairly flat in areas where it was only recently removed, which is why the area is now called the Santa Rosa Plateau.
- The Santa Rosa Plateau is the only place in Southern California where you can easily see what the terrain was like 10 million years ago.