Arcata
It's easy to hitchhike to Arcata, California! Starting from 101 in Golden Gate, San Francisco there are some great spots to pick up rides all along 101. Try to get out of the Bay Area quick if you can as the California Highway Patrol will be on you if you attempt to hitch on the 3 lane highways. You shouldn't have many problems on 2 lanes roads. The farther North you go the easier it gets! Most people can recommend good spots. Avoid rides to Ukiah as there are no good spots to hitch from - 101 turns back into a freeway there. Hopland is a great spot to hitch, especially on the straight run near the Solar Living Center! Laytonville is a great spot! Willets is really tough spot for cars to stop!
To leave Arcata going east to Weaverville/Redding on Highway 299, you can catch rides at the 101 North exit just at the north edge of town, 17th and G St, right at the pedestrian bridge to Humboldt State.
