I have been living in Manhattan Kansas for the past 4 years and looked for the grade on Google maps satellite view. The route is shown on old county maps and you can pick out parts of the grade on the satellite images but most of it seems to be ploughed under.
One time I drove north of here to see if I could pick out where it ran down to what is now Tuttle Creek Dam but I think at this point Baldwin Creek Road runs down the top of it and I couldn't see anything that looks like a railroad grade.
I haven't tried to find any of the parts that show up in the satellite images. If I had the skills of ROW Explorer I would overlay the route from the old maps on the modern "satellite" image.
Ken