| Mark | Athlete | School | Year | Meet |
|---|
| 49.34 | Kohbe Smith | Dawson Co./Glendive (A) | 11 | State A Championship |
| 49.62 | Treyton Graham | Beaverhead Co./Dillon (A) | 12 | Western A Divisional |
| 50.20 | Gavin Garrison | Beaverhead Co./Dillon (A) | 12 | State A Championship |
| 50.39 | Derek Criddle | Corvallis (A) | 11 | Western A Divisional |
| 50.60 | Eli Taylor | Hamilton (A) | 12 | Western A Divisional |
| 50.74 | Kade Boyd | Billings Central (A) | 12 | Eastern A Divisional |
| 50.78 | Gideon Boswell | Corvallis (A) | 10 | State A Championship |
| 50.88 | Malaki Simpson | Columbia Falls (A) | 11 | Whitefish ARM Invitational |
| 51.00 | Carter White | Frenchtown (A) | 12 | Western A Divisional |
| 51.08 | Clay Oven | Billings Central (A) | 12 | Eastern A Divisional |
| 51.59 | Kaeden Sager | East Helena (A) | 12 | John Tomich Invitational |
| 51.63 | Drifter Skillicorn | Polson (A) | 12 | Nelson-Thomas ABC Meet |
| 51.73 | Riley Cline | Custer Co./Miles City (A) | 12 | Sidney Invitational |
| 51.87 | Reid Malcolm | Park/Livingston (A) | 12 | State A Championship |
| 51.90 | Max Cianflone | Hamilton (A) | 12 | State A Championship |
| 51.93 | Avery Crouse | Fergus/Lewistown (A) | 12 | Eastern A Divisional |