I'm in zone 3B and have had good luck growing Haralson, Sweet 16, Chestnut Crab, and State Fair. Other apples that other people have/can grow around here include the following : Duchess, Fameuse, Fireside, Freedom, Hoanneycrisp, Honeygold, Prairie Spy, Wolf River, and Yellow Transparent. St. Lawrence Nurseries in Potsdam is specifically tailored for the zone 3 and 4 grower.

Here is a link that might be useful: St. Lawrence Nurseries

We have a couple of old apple trees, Beacon and Haralson. They are good producers but they tend to bear heavily one year, then take a year off. I suppose I could prune off some of the fruit on the "good" years and maybe it would even out :) The University of Minnesota breeds fruit trees for cold climates, check out their web site for some good cold hardy varieties.

Here is a link that might be useful: U of M Extension - fruit

Try this link ... www.botanicalgarden.ubc.ca

There are many threads in the "Far North" forum dedicated to this topic. I'm in a much "harsher" climate than you (Northwestern Alberta, USDA Zone 1B), and yet there's a wide range of fruit trees that are available -- and will thrive -- in the north. "Norland" and "Parkland" are excellent apple varieties for cold-winter areas, and I can't recommend Nanking cherries highly enough. While it's true that they don't approach sweet cherries in size and taste, I always get a great crop and they're really tasty. I have a "Golden Spice" pear, but it's not really thriving and seems to be susceptible (advertising notwithstanding) to fire blight.

Finally, no northern garden is complete without a stand of saskatoon bushes. They're extremely productive and rank with the best of all fruit in taste.

FWIW, my growing season is about 100 days, and we can usually count on a snowfall or two in May...although it snowed on June 4 this year.

I guess I should go out and sample the saskatoon berries. I always let the birds have them!