I am not an expert, being from zone 7, but i've seen a couple of lists for Alaska and Canada. Here's some links to get you started with. Good luck. RJ

http://www.alaskahardy.com/plants/plants1.html

http://www.args.org/ Alaska Rock Garden Society

http://www.canadianliving.com/CanadianLiving/client/en/Crafts/DetailNews.asp?idNews=1217&idSM=308

http://www.nargs.org/gardening/plant.list4.html

It sounds as if you are new to rock gardening. If you mean alpine rock gardening, there is also a chapter of the North American Rock Garden Society in Ontario. What they grow will be more useful to you than Alaska's. Many natives that grow in Alaska cannot tolerate the heat and humidity of Ontario (or Minnesota).

Here is a link that might be useful: Ontario Rock Garden Society

Try High Country Gardens for ideas:

http://www.highcountrygardens.com

They tend to be really conservative about zones. If they sayzone 4, it should have no problems!