Collection location: Jedediah Smith State Park, Del Norte Co., California, USA [Click for map]
Having never seen this species , I had some initial id problems. However, they did fit Thiers’ and Arora’s descriptions nicely. In addition the caps seemed to bruise red when they were scratched, which doesn’t seem to have been noted before (?).
In my reading about B. smithii, it seems this one has a very thick red layer benieth the surface of the cap. Also the surface of the cap is very fiberous/powdery (kinda), and Thiers mentions that most of the time the surface wears off leaving the red layer exposed, so the mushroom looks mostly red in the cap.
But I would think at a certain thickness of the surface, it would look like it would turn red when scratched, since you are scratching through the surface, and exposing the thicker, stronger red layer benieth.
But I am just guessing here, since I only saw this once (maybe), and going by what I read in Thiers boletes of CA.