I have heard that the further south you go on the Pacific Coast, the worse it gets for hiker biker sites.

I rode from Astoria to San Francisco in 2014. Twice reported some unsavory types to park rangers.

First was a big guy walking into my camp area with a large dog, he apparently did not see me at first, he was about 20 feet from a picnic table with a lot of our stuff on it. When he saw me, he seemed unsure, should he pretend he is innocent or threaten me with his dog. I pulled out my phone and opened it up (flip phone) so I could call 911 if I had to, he then chose to leave after saying that he paid taxes and had as much right to be there as I did.

Second time was two homeless people that moved into our site after we called it a night. Ranger chased them out.

I think part of the problem is how the staff treats their campers at campsites. In Oregon, the park staff were great, very helpful. In California I started to give some constructive criticism to a park staffer, and she immediately informed me that we were very lucky that they allowed us to have hiker biker sites because we were low revenue and the RV owners were the ones that deserved good service. At other California parks, I found the attitude to generally be similar to that. When that poor attitude of not supporting hiker biker site users is prevalent, that encourages the lawless faction to take advantage of that.