Not a very good gardener, but will toss in my two bits.
You can embark on a full scale battle to amend your clay and slowly, over YEARS and with much sweat and weeping, attempt to make it into a workable soil. OR skip that step and haul in something to garden in.
If you want to plant acres of garden and can and freeze and pickle and dry, then you might have to undertake the Clay Busting Battle. However, if small scale is more your style, I would consider raised beds. With good sun exposure, water and good soil, you can produce a lot out of raised beds! And the bonus is in ALberta, with your shorter growing season, a raised bed heats up sooner and gives you a short jump on the growing season, you can plant them a bit sooner (cover for frost protection).
I have built two hugelbeets here. Google it. Essentially a deliberatey constructed pile of the following: bottom layer, dead wood. Trunks, large limbs of DEAD trees laid raft-like on the ground. Over this you dump rotted organic matter like leaves, lawn clippings, straw/hay that had been piled and heated for a year, hopefully to kill off most of the seeds. Over the organic matter you pile your soil. Now it looks like you've buried something in your yard. I call mine the burial mounds. The rotting of the wood and organic matter add heat to your soil and again, jump starts the growing season. Each year you can add a bit more manure/soil to the top and plant away. These are obvioulsy not good for crops like carrots or beets. But for melons, zuchinni, squash, cucumbers, the BIG plants they work great! Also a good way to use dead brush without having to light a big fire. But make sure it's DEAD! Willow trunks can look dead and when you bury them, the darn things start to grow and you have a forest in your hugelbeet.
I think your decision will be determined by how BIG you want your garden. ANd if you have materials to build raised beds and someone to swing a hammer. But if it was me, I'd leave that clay where it was and not disturb it.