Interstate 5 is currently closed between Redding and Mt. Shasta due to another major wildfire burning on both sides of the Freeway.
This fire, named the Delta Fire, started yesterday (9/5/18) and forced a quick evacuation of the highway - emergency crews used the median cutouts to turn cars around, and several Semi Trucks had to be abandoned, at least a handful of which have been destroyed by the fire. There have been no injuries reported so far, but it looks like Interstate 5 could be closed for quite some time.
To avoid the closure, drivers can take CA-299 east from Redding to CA-89 and take that back north to Mt. Shasta, going right past McArthur-Burney Falls State Park. That's a 120 mile drive on 2 lane roads, and will likely be seeing very heavy traffic and delays. Travelers looking to head from LA/Sacramento/Bay Area to Oregon or Washington may want to look at other alternate routes, including using US-101 to US-199.