| Mark | Athlete | School | Year | Meet |
|---|
| 49.68 | Pres Harris | Plentywood (B) | 12 | Miles City Invitational |
| 49.71 | Marc Swan | Manhattan (B) | 12 | Midland Roundtable Top 10 Meet |
| 50.04 | Dustin Sobrero | Columbus (B) | 11 | 4B Districts |
| 50.14 | Doug Raymer | Darby (B) | 12 | Western C Divisional |
| 50.14 | Isaac Howard | Choteau (B) | 12 | 1B Districts |
| 50.43 | Jacob Senecal | Powell Co./Deer Lodge (B) | 12 | Western B Divisional |
| 50.60 | Cale Howells | Manhattan (B) | 12 | Southern B Divisional |
| 50.69 | Dylan Reynolds | Florence-Carlton (B) | 12 | 6B Districts |
| 51.10 | Brady Blomquist | Florence-Carlton (B) | 12 | 4-21 Seeley-Swan Invitational |
| 51.54 | Dylan Surber | Chinook (B) | 11 | 4-21 Cut Bank Invitational |
| 51.74 | Andy Nordstrom | Red Lodge (B) | 10 | 4B Districts |
| 51.91 | Kodee Varner | Baker (B) | 12 | 3B Districts |
| 51.94 | Beau Milton | Joliet (B) | 12 | Southern B Divisional |