There are a number of swing bridges on the Red River of the North, from the mouth at Lake Winnepeg south to Fargo. I've only eyeballed them with Google Earth, but I'm unable to get to that area myself. Have at 'em, Tony...
There was likely (originally) a through truss swing at this location, and when the present bridge was installed the swing mechanisms were removed.
The round center pier usually indicates that it was built as a swing bridge. But there is none of the hardware that would indicate that this bridge ever was a swing bridge.
Yes, like others over the red river, this one used to be a swing bridge. I can't find the picture now but it was a steel truss bridge.