9: newly created as renumbering of 91 to avoid conflict with US 91
10: renumbered to 7 to avoid conflict with US 10 (one part would be transferred to 30 later)
11: transferred to US 12 east of Miles City and US 10 west of Miles City; reused as renumbering of 76
12: renumbered to 15 to avoid conflict with US 12
13: newly created as renumbering of 18
14: section from Miles City to Glendive transferred to US 10
15: newly created as renumbering of 12
16: unchanged
17: renumbered to 5; reused as renumbering of 20
18: renumbered to 13; reused as renumbering of the part of 55 not cosigned with US Routes
19: newly created as renumbering of 32
20: renumbered to 17; newly created as renumbering of part of 33 and all of 69
21: new road
22: unchanged
23: new road
24: newly created as renumbering of 77
25: newly created as renumbering of 30
26: new road
27: newly created as renumbering of 34
28: new road
29: newly created as renumbering of 68
30: new road, also replacing part of 10
31: newly created as renumbering of part of 86
32: renumbered to 19; reused as renumbering of 42
33: renumbered to 3, 6, and 20; portions transferred to US 93, US 10, and US 10 alternate; note that one section was removed from the state highway system reused as renumbering of 88
34: renumbered to 19; reused as renumbering of 71
35: eliminated; reused as renumbering of 92
36: newly created as renumbering of 90
37: newly created as renumbering of 94
38: newly created as renumbering of 87
39: new road
40: transferred to US 310; reused on new road
41: newly created as renumbering of 72
43: newly created as renumbering of part of 86
45: newly created as renumbering of 57
55: renumbered to 18; Grassrange to Armington transferred to US 87W; and Glendive to North Dakota transferred to US 10
57: renumbered to 45
60: renumbered to 187
61: eliminated
62: eliminated
63: eliminated
66: transferred to US 87W and US 87
68: transferred to US 91 from Great Falls to Wolf Creek and rest renumbered to 29
69: renumbered to part of 20
70: renumbered to 191
71: renumbered to 34
72: renumbered to 41
76: renumbered to 11
77: renumbered to 24; east of Marion and west of Libby transferred to US 2