Montana 42 map courtesy of Google Earth
| Length |
| 2.9 miles |
| Other names |
In Glasgow: 6th St. N.6th St. S. 1st Ave. S. |
| Northwestern terminus |
| Glasgow, Valley County, JCT US-2 |
| Southeastern terminus |
| Valley County, JCT MT-24 |
| Municipalities traversed (NW to SE) |
 Glasgow |
| Road intersections |
| US-2 TRUCK MT-42 MT-24 |
| Notes |
| The route was formerly named MT-24W (one can tell that the MT-24W shield was covered with a MT-42 shield on US-2 near 42's terminus). TRUCK MT-42 uses 4th St. to reach US-2, probably in order to avoid the railroad overpass on 6th St./MT-42. |