Shelf fungi (a leathery conk) growing on fallen (most likely) Douglas Fir log.

Northern Red Belt (Fomitopsis mounceae) is a "perennial woody conk distributed across Canada and the northern United States, down to Santa Cruz County. It is typically fan-like in shape, with distinct bands usually brown or red in color. It can have a resinous, sticky coating. As the conks age, they often become bumpy or warty. The underside of the conk is typically white or yellow in color. If broken open, the inside is woody and brown, with no distinct bands." https://www.inaturalist.org/taxa/877361-Fomitopsis-mounceae

Polypores (Conks, Bracket Fungi, etc.) Leathery conks or brackets, typically perennial, occasionally annual and fleshy; fertile layer poroid, less commonly gill-like, labryinthoid, or tooth-like, not readily separable from the rest of the fruiting body. https://mykoweb.com/CAF/skey.html

Fungi of California: Home page https://www.mykoweb.com/index.html and https://www.mykoweb.com/CAF/ and https://mykoweb.com/CAF/skey.html and https://www.mykoweb.com/CAF/keys/index.html (species not listed?!)

Mushrooms of the Redwood Coast: A Comprehensive Guide to the Fungi of Coastal Northern California, N. Siegel and C. Schwarz, 2016, p 458- (species not listed)

California Mushrooms: The Comprehensive Identification Guide, D. Desjardin, M. Wood, and F. Stevens, 2nd printing 2019,
Key to Polypores, pp. 378-379 (species not listed)