The western side of North Dakota is a veritable speed trap. I was headed to Minot, North Dakota several years ago, and was the only one on the highway it seemed, and all of a sudden a cop car came over a hill, turned his lights on, pulled me over. I was going 65 in an unposted 55 MPH stretch of 2-lane highway about 3 hours west of Minot.
Stanley, Tioga, and Ray are the only speed zones I know of there once you get clear of Minot, besides Williston.
Unless you were waay up north and heading west along the high line, that is.