| Mark | Athlete | School | Year | Meet |
|---|
| 49.23 | Derek Criddle | Corvallis (A) | 12 | State A Championship |
| 49.27 | Kohbe Smith | Dawson Co./Glendive (A) | 12 | Glendive Shriners Invitational |
| 49.73 | Evan Bennett | Hamilton (A) | 11 | State A Championship |
| 49.78 | Carson Krack | Whitefish (A) | 12 | State A Championship |
| 50.44 | Jack Phelps | Columbia Falls (A) | 11 | Archie Roe Invitational |
| 50.60 | Beck Whicker | Custer Co./Miles City (A) | 11 | Eastern A Divisional |
| 51.17 | Samuel Jagodzinski | Billings Central (A) | 11 | Eastern A Divisional |
| 51.24 | William Snell | Billings Central (A) | 10 | Billings Invite |
| 51.71 | Alec Dalby | Park/Livingston (A) | 12 | Eastern A Divisional |
| 51.76 | Gage Gunther | Custer Co./Miles City (A) | 12 | State A Championship |
| 51.79 | Miles Wells | Hardin (A) | 12 | Laurel Iron Horse Meet |
| 51.88 | Ethan Amick | Whitefish (A) | 11 | Whitefish ARM Invitational |