| Mark | Athlete | School | Year | Meet |
|---|
| 39.83 | Lee Walburn | Whitefish (A) | 12 | State A |
| 40.06 | Chris Abell | Laurel (A) | 12 | State A |
| 40.37 | Cutter Thatcher | Butte Central (A) | 11 | Western A Divisionals |
| 40.72 | Aidan Barrows | Custer Co./Miles City (A) | 11 | State A |
| 40.85 | Camden Capser | Billings Central (A) | 10 | Class A Eastern Divisionals |
| 41.06 | Justus Peterson | Beaverhead Co./Dillon (A) | 11 | State A |
| 41.07 | Kaden Stradley | Custer Co./Miles City (A) | 12 | State A |
| 41.31 | Treyton Anderson | Beaverhead Co./Dillon (A) | 9 | Western Top 10 Meet |
| 41.51 | Logan Peila | Custer Co./Miles City (A) | 11 | John Polich Invitational |
| 41.56 | Zackary Pletcher | Columbia Falls (A) | 12 | State A |
| 41.65 | Tyler McDonald | Frenchtown (A) | 12 | State A |
| 41.68 | Matt Netley | Park/Livingston (A) | 12 | State A |
| 41.70 | Cameron Egan | Dawson Co./Glendive (A) | 10 | State A |