I was Southbound and was going to proceed past the sign thinking that a bike can always get through some way or another but a hand-written sign next to the official sign said that it was also closed to bicycles. I had started in Nehalem that day and was feeling too tired to gamble riding a few miles up the hill only to have to turn around and head back so just proceeded on the busy 101 over the pass (not fun on the big weekend with heavy traffic).
Another thing that may be of more interest to people on this section is the route and location of the campground at Devils lake campground. The map sends you around the east side of the lake and that's were the camping appears to be located but that's a day use area on that side. The camping is located on the west side of the lake. (if you're as tired as I was that day) you might consider staying on 101 (yes, busy crowded 101) and enter town on the west side of the lake. That's were you'll see the sign directing you to the campground.