The California black oak snuck in when the price of real estate to the south made it worthwhile to relocate, but they only migrate about as far as Roseburg. Their bark is dark and the acorns are one to two inches long with deep pockets, I mean, caps.

http://mailtribune.com/lifestyle/the-tales-acorns-can-tell

It is late in the day and still very hot—approaching and possible reaching 100 degrees—and, besides that, it’s a Wednesday, so I think there’s no way anyone’s going to be out looking at trees. But I have underestimated the human ability to disregard nature when trying to commune with it.

https://www.lamag.com/citythinkblog/secret-life-of-trees/

Oak trees are the powerhouses of California's native ecosystems, and now the non-profit California Native Plant Society has launched a statewide effort to help restore and grow native oak populations up and down California.

https://www.benzinga.com/pressreleases/18/11/r12735911/california-native-plant-society-announces-re-oak-california