If you look at it on a map, Point Reyes Peninsula, on the seashore north of San Francisco, looks like it is breaking off the continent. It looks that way because it is doing just that. Both Point Reyes and the part of California it is attached to are in motion, as is every other part of the Earth; they are on different plates in the earth's crust and are headed in different directions, Point Reyes slowly moving northwest along the coast. Between them is the famous San Andreas Fault, the fault line that slipped in 1906 and destroyed San Francisco. A visit to Point Reyes is also a visit to the San Andreas Fault, and if you know where to go, you can see it up close.
Instructions
1. Go to the Point Reyes Peninsula; as you get close to the peninsula, look for the small town of Olema. Quite close to Olema is the Bear Valley visitor center, beside the headquarters for Point Reyes National Seashore. The visitor center is off Bear Valley Road, which intersects with California State Route 1 at Olema.
2. Go to the Bear Valley visitor center. Rangers there can answer any questions you have. You can also pick up a map of Point Reyes National Seashore here. On the other side of the entrance road to the visitor center, you will find the trailhead for the Earthquake Trail.
3. Walk or drive to the Earthquake Trail trailhead, then hike the Earthquake Trail. This loop trail is 0.6 miles long, or one kilometer. The trail is paved and accessible for the disabled. It takes you directly through the San Andreas Fault zone. The National Park Service has put in an extra effort on interpretation here. The fault itself is marked with light blue posts, so you can follow the exact fault line as you walk over it. At short intervals, the park service has also put up signs explaining what you are seeing.
4. Look at the offset fence. The trail goes past a wooden fence that was here during the 1906 San Francisco earthquake. When the fault line moved, it broke the fence in two and moved the two halves 18 feet apart. This is one of a number of points on the trail where you can see and understand the motion of the two plates that slide past each other.
5. Look for the San Andreas Fault throughout the rest of your visit to Point Reyes. It is a constant presence: it runs under Tomales Bay, under the town of Olema, up the valley in which Olema sits, and under Bolinas Lagoon. It gives the region its distinctive shape, and you can see it clearly even on a map that does not label the fault.
Tags: Point Reyes, Andreas Fault, visitor center, Bear Valley, Earthquake Trail, fault line
