Gazos Creek Road is officially closed from the junction with Cloverdale Road (which is open) to the gated entry to Big Basin, just past where the burned-out box cars are pictured. You can get through on a bike. The off-road up-hill section from where the paved part ends is quite challenging.
Gazos Creek Road is open between Highway 1 and Cloverdale Road.
I do not know the status of Butano Fire Road.
I misunderstood and thought you were asking if you can complete a loop. (You can.)