I'm in Fairbanks and not sure how different we are (other than less rain?). I typically start seeds in April and plant Memorial Day weekend. This year the harvest ran longer because of the looong fall
The Alaska Gardening Guide is a very good ref. book for what and when and how to plant.
Moose are my main problem here as well. I had a great fence and they just trampled it down. They ate everything!!!! To add insult to injury, our neighbor shot the moose during hunting season...I'm a vegetarian, but I asked him how he liked the lovely leek and kale undertones to his moose meat.
Well, I don't know about Alaska but I am in Zone 3 too. I usually start plants inside in April too, some at the end of March and plant outside labor day weekend. I look for fast growing seeds, and winter hardy fruit bushes ect. Sounds like moose may be a problem for you, good luck! We have some around here but not too many, deer and rabbits are the biggest problem here.
We do have a greenhouse and a regular garden. We built the greenhouse using plastic tubing (pvc electric tubing?) and vapor barrier plastic sheeting to cover. I grew tomatoes, eggplant, peppers, celery, bok choy and cukes.
I planted typical cold weather crops in the regular garden: potatos, leeks, peas, garlic,kale, spinach and green beans. This year, I plan on brussel sprouts, cabbage, broc and cauli. in the cold weather garden as well.