I've seen lots of Alberta plates at Mabel, Christina, Shuswap, Okanagan and Kalamalka lakes in BC.
I've also heard of skiing in the Bow River, but I don't know exactly where. There's also Chestermere Lake (also nicknamed "the Slough").
A lot of us invade BC every summer as our lakes suck. We frequent Osoyoos every year. And I am certianly aware of "Chester-slough". :/