I think the grass is Smooth Brome. Very prevalent here along the railroads and hiways.
Before the dam, when the bridge was built, the major threat was ice jams. A couple years before the real bridge was built, the local Wolf Point businessmen got together and had a wooden pontoon bridge constructed about 4 miles upstream  that came right into the old town of W.P. Plan was to take it out of the water before freeze-up and re-float it in the spring after the ice went out. Wouldn't you know it but the very first fall it was used, a sudden and early cold snap froze the shiny new bridge into the ice and it was wrecked the next spring when the ice went out. I'm sure that the recent episode with ice left an impression on the planners and influenced the design somewhat.
When the bridge was being built, a spur line off the GN RR was built to get supplies to the site from the mainline which was about 3 miles away. Wooden coffer dams were built and sunk into the bottom mud. They were pressurized to keep water and mud from oozing under the bottoms as they were dug out and allowed to settle and as you might imagine, workers in the coffer dams suffered from what we now call 'the bends' when they came out to natural atmospheric pressure. Quite a boom town grew up on the north bank of the bridge site.  The Bridge Club was the hot spot for socializing and there were unattached ladies for hire there too. Mysteriously, when the construction finished and the powers that be decided it was time to become a bit more respectable, the Bridge Club caught fire and burned to the ground. Nite club that grew up on the south side of the bridge continues to this day although the same range of services was offered there at the time too. Now it's respectable enough that we take distinguished NAT visitors there for a steak supper. Times change . . .