Additional suggestions by Dave

I meant that I could not ride the entire Alcan highway. It is too long. Also it is an easy day drive from one city to the next with motels but by bike alone camping would be necessary. By car - gas, food, motels, cities are easily available. But the ~300 miles separation is too much by bicycle each day. Having said that I did see a couple dozen cyclists doing the entire route. It is spectacular.

As you found, there are regular bicycle rides from Haines to Skagway. This is 350 miles and 22,000 ft of climb but not bad gradient this way. However the reverse is a steeper climb out of Skagway. There also was the Fireweed 400. The 400-mile race went from Sheep Mountain Lodge to Valdez and back and was a qualifying race for the 2,980-mile Race Across America (RAAM). It also included races of 50, 100 and 200 miles. 

The 200-mile race, which started at Sheep Mountain Lodge on the Glennallen Highway and ended in Valdez, was the most popular of the events. This is the race that Brian participated in 3 years ago. It attracted hundreds of riders each year. I rode (not raced) part of it with my grandchildren while Brian was huffing it out with his relay team. But I just read that it was cancelled in 2019. Like rides around here it was just took too much effort to organize.

To make this a longer tour, we could start in Haines Junction, ride to Skagway, Ferry across to Haines, then ride up to Haines Junction. From there we could head NW on the Alcan to Tok then down AK Highway 1 to Glennallen and SW to the Sheep Mountain Lodge. 850 miles and 64K Ft of elevation. Or we could shorten it by 200 miles and start in Haines. While in Yukon Territory we would have to plan carefully for motels.

Anyway we did this, it would be a very memorable ride.