Did you know that the Wallowas are the site for the only qualifier for the Iditarod in the lower 48? The event is called the Eagle Cap Extreme and it’s held every January.
So, I’d recommend getting in touch with the organizers for more detailed information about routes in the Wallowas, and there are lodgings that accept dogs as well, including Barking Mad Farm.
That should certainly get you started in the right direction. Let me know if you need any more on-the-ground information.