I don't know what your ability is to buy passes on other carriers but I WILL recommend flying ANC/SEA with Alaska. We generally offer 18-20 flights a day in the summer months so, barring weather problems or something, you should have no problem getting on a flight. Once you are in SEA you can take a DL flight. Consider an alternative ANC/ORD on us but, with only one flight a day you would be in the same pickle as you would be with DL. Even though we offer a nonstop ANC/YVR flight in the summer, I would NOT recommend that one. YVR is really difficult to non-rev from in the summer in spite of the number of flights. Smaller plans, you know. I have tried to rebook people on DL/CO/AA out of ANC in the summer (I'm a change agent with AS) and the flights are always packed.

Make sure you go see the fishing in the river before you leave Anchorage. They call it "combat" fishing. Fascinating. People are lined up practically shoulder to shoulder and there are strict rules as to how you can catch something. We spent about 40 minutes watching and talking to the fishermen and it was a riot.