I highly recommend spending some time hiking in the Hoh & Quinault temperate rainforests in Olympic National Park. It's a beautiful and unusual forest. There is also a separate ocean beach section of the national park near La Push. The wild beach is gorgeous and is best visited at low tide. The tide times are posted there and in visitors centers, and also online.

About 20 miles after you cross into California from Oregon, you will enter Jedediah Smith State Park. As I recall, heading south in Jedediah Smith State Park, you are initially in second growth redwood forest. But you will soon enter an impressive old growth redwood forest and it is extraordinary. I was cycling with a European friend and he was blown away when he first saw an old growth redwood forest. You will be in and near many other old growth redwood forest areas in Redwood National Park and California state parks as you continue south.

Lots of interesting things to see and do along the California coast depending on your interests. The funky Santa Cruz boardwalk, Hearst Castle in San Simeon at the south end of Big Sur, gardens in Santa Barbara. If you happen to be in San Luis Obispo on a Thursday evening, there is a great outdoor farmer's market well-known for its BBQ.