| Mark | School | Meet |
|---|
| 43.26 | Stevensville (A) | State A Track Meet |
| 43.30 | Billings Central (A) | State A Track Meet |
| 43.98 | Custer Co./Miles City (A) | Eastern A Divisional |
| 44.07 | Corvallis (A) | State A Track Meet |
| 44.40 | Columbia Falls (A) | Northwestern A Divisional |
| 44.60 | Frenchtown (A) | Missoula Quad |
| 44.76 | Laurel (A) | 4-10 Billings Senior Meet |
| 44.84 | Beaverhead Co./Dillon (A) | State A Track Meet |
| 44.93 | Libby (A) | Northwestern A Divisional |
| 45.03 | Hardin (A) | Midland Roundtable Top 10 Meet |
| 45.04 | Bigfork (A) | 7B Districts |
| 45.10 | Hamilton (A) | State A Track Meet |
| 45.47 | Dawson Co./Glendive (A) | Jock Stop Meet |
| 45.49 | Polson (A) | Polson ABC Meet |