Uh... there are always ways.
We have a railroad, even if for some obscure mechanical reason the diesel electric engines cannot run we have steam powered engines.
I can imagine now a New Alaska rising from the ashes of a global war, all our transportation is done by steam, fuel is from CNG available to all, natural gas heats the homes, fuels the cars, trucks and trains. The foraging moose by the thousands are now corralled and harvested for meat.
Many farms in the Mat Su Valley now raise their own moosemeat.During the summer months we grow half ton cabbages and meter long carrots. All fishing regulations have been discarded, many non natives who used to rely upon the stores now smoke fish, can veggies and build giant pantries at home.
Meanwhile those in Anchorage begin to starve without their Federal assistance checks, they riot, they freeze, they eat their wounded.
Sadly the Knik River Bridge is now a fortified gate limiting access of the Anchorage Zombies.
Yep, The Iditarod only takes anywhere from 9 to 15 days and at least six out of twelve dogs in the team have to survive. Alaska is a BIG state.