In 2016 I put all new tires on the entire rig. New Michelin's on the F-550 and new tires on the trailer. Truck because at 60,000 miles they were shot and trailer which we bought used just to trash on the Alaska Adventure were 8 years old and out of my tire age comfort range. Put higher Load Range tires on the trailer for the trip. I took one spare for the truck and two for the 5-er. Never had a tire issue during our 8,000 mile, 3 month trip.
If you plan to venture up to Inuvik or Prudoe Bay then spares are a must.
After living up there for 25 years and venturing around most of the state, Yukon and BC I've seen lots of motorists with flats, lost exhaust systems, failed drive line U-Joints and some nasty wildlife collisions over those years.
On road that is very unpredictable is the hwy between Tok and up through Chicken on your way to Dawson City. I've crossed it a half dozen times and every time it's in a different condition. My first time was years ago in a 4x4 Dodge. It had new tires. There were several sections of shot rock paved road and we came across several vehicles that had flats that looked like they had been put through a tire shredder. We stopped and all had spares but all were travling and had a vehicle full of stuff and had to unload behind the vehicle to get to their spare.
The Alaska Hwy was built by the USofA. When it was given to the Canadian Govt. part of the deal was the US would fund road maintenance. For multiple years the US did not ear mark funding to maintain the Alaska Hwy Canadian Portion which is a majority of the route. If they did they threw chump change to the Canadian Govt sort of like they do the US Interstate system.
But it's been 30 years since my 1st trip to move to Alaska and the Hwy is vastly improved from back in the day. They Alaska Hwy is short now then back then since they have straightened many sections from when the original road was built for the US Military. This has resulted in the travel distance being shorter from start to end then original road. They have also done a lot of safety improvements by doing large cut backs of brush and timber from the Hwy so animals are much less likely to pop out onto the road right in front of you. Cutting down on accidents, injuries and fatalities. One trip I came across a Ford F-250 that had hit an adult moose. The front end of the pickup was relocated to on top of the engine and the moose was in the windshield of the cab.
2006 F-550, Crew cab, 4x4 w/factory bed getting 12 mpg @ 50,000 miles
2006 Lance 1191
2006 Wells Cargo 14' Cycle Wagon
2017 Grand Design 5th wheel with EezTire TPMS
2017 F-450 4x4 crew cab King Ranch