Northbound - after leaving Greenville and making the climb (+/- 1000') to Lake Almanor, take CA 147 towards Westwood. Before you reach CA 36 (near Clear Creek Park), take a right at County Rd. A21 and continue through Westwood. After crossing 36 continue north to CA 44. Continue North/West on 44 until it intersects CA 89 at which point it rejoins the route. The only drawback to this is you will very likely be in the smoke plume from the fire - not the best. Suppose you could go further east before turning north at either CA 139 or as far east as US 395 (there's a fire out there too). CA 139 would take you to US 299 which you could then take to the west to pick up 89. It is a long way around and I cannot vouch for services on 139 between Susanville and 299. I've been studying the route but had not gotten to researching the services. There are some back roads in the 299 area that can keep you off 299 and headed NW. Services are few and far between once you're away from the main roads. I've ridden some of these roads, but not all. If you decide to go the 139 route I have a contact in Burney I can rattle to for some additional advice. Best of luck -from the incident page, it doesn't look like 89 through the park will open for some time.
Santa Rosa, CA