I think it's not just a matter of man-made structures being gone. Look at 0:31 of this video[1], the giant bright ember on the left is the iconic tree[2] by the visitor center. Having seen what burning firewood looks like, I would be extremely surprised if that tree managed to survive that. And judging from the extent of the damage, most of the most memorable trails in that park are probably also completely destroyed.

I'm glad I had the chance to visit this park last year, but also sad to see its apocalyptic state on top of everything else that already happened this year.

[1] https://www.ktvu.com/news/californias-oldest-state-park-big-...

[2] https://s3-media0.fl.yelpcdn.com/bphoto/_aLLH1G53QxyzKCleBGw...