Ice-harvesting used to be widespread before the time of artificial ice. I have seen photos of ice-harvesting around Calgary and Edmonton in Alberta, and of the storage buildings. These supplied a fairly local market, but the Kennebec and others were a large business.

It is amazing how long ice storage pits will keep cold. Doing biological field work in Texas, we dug a pit, lined it with straw, and stacked large blocks of ice in it (the ice commercially produced in the nearest city). Temperatures were often high, but our ice cream, beer, meat, etc. were kept cold over the entire summer.

The ice roads (February-March best) across Great Slave Lake and on north to Inuvik are hard and fast at the height of the winter season; only at the fag end of winter do things become dicey. The four-foot thick ice road on Great Slave (The Blue Highway) sees rigs weighing 150,000 pounds and more going to the mines. Haven't heard any songs (No 'Diamond Rush'- everything commercially staked and evaluated).
http://www.roadstaronline.com/1999/06/9906134.asp

Winter was the time to take the Alaska Highway as well- the mud of summer is killing.