Unfortunately you're probably going to have to cross-section it to get an idea what the internal structure looks like.
It might also help to get a specific gravity on it to understand better what it might be made of. Is it Bone, Rock, Ivory, Enamel, Wood, etc...
Obviously it looks like a large tooth, but that could be pure coincidence. Orca teeth look like that. If it's a tooth, it's from a carnivorous animal, very large. Today that pretty much leaves Orcas and Sperm whales. If it's prehistoric, then it would be fossilized and no bone or tooth would remain (thus the specific gravity test).
Since you live in Manitoba it might be an old discarded Orca Tooth.