ND 9 originally extended to Canada, and at its current eastern terminus, it followed the route of what is now ND 1 south, but when US 52 was extended into North Dakota, ND 9 was truncated to its current terminus.
Originally extending to Canada, ND 9 followed the route of what became ND 1 south. When US 52 was extended into North Dakota, ND 9 was reduced in length to its current end point.