About 100 miles north of San Francisco, The Sea Ranch stretches along 10 miles of coastline. When the ubiquitous fog thins away, it takes a second to see the silhouettes of the low-slung houses, the meadows, the forests, and the bluff. Then the fog returns, and they seem figments of imagination. Were those really houses tucked against that cypress row? How could it all blend so effortlessly?