| Mark | Athlete | School | Year | Meet |
|---|
| 39.56 | Haiden Collins | Fergus/Lewistown (A) | 12 | Midland Roundtable Top Ten |
| 40.35 | Anders Westman | Beaverhead Co./Dillon (A) | 11 | Gallatin Valley Invitational |
| 40.60 | Tyler Burk | Custer Co./Miles City (A) | 12 | Jock Stop Meet |
| 41.24 | Danny DiGiallonardo | Polson (A) | 12 | Western A Divisional |
| 41.32 | Connor Lanier | Polson (A) | 10 | ABC Invite |
| 41.35 | Jansen Anderson | Beaverhead Co./Dillon (A) | 12 | State A |
| 41.58 | Malik Toure | Hardin (A) | 11 | State A |
| 41.69 | Garrison Hughes | Sidney (A) | 11 | Eastern A Divisional |
| 42.00 | Michael Hoerner | Columbia Falls (A) | 12 | State A |