Today this portion of 1st Street is pretty much all civic buildings and offices, with the exception of the Ewart-Duggan House which is just a few doors down from where this postcard was photographed. The only real giveaway to the location in this picture is St. John's church peaking through in the background. I returned to the corner to try and get a modern image of the location today.
The back of the postcard is dated August 15, 1917 and is addressed to someone in Calgary. The fact that it isn't postmarked tells me that it was sent with someone who was making the trip there. It's a pretty fascinating find given how much has changed on that corner in nearly a century.