| Mark | Athlete | School | Year | Meet |
|---|
| 38.10 | Landon Polkow | Billings Skyview (AA) | 11 | State AA Track Meet |
| 39.63 | Jacob Leininger | Glacier (AA) | | Swede Dahlberg Invitational |
| 39.83 | Landon Polkow | Billings Skyview (AA) | | Billings Invitational |
| 39.95 | Kody Berget | Libby (A) | | Western Montana Top 10 |
| 39.95 | Stephen Delaney | Charlo (C) | 11 | Western Montana Top 10 |
| 39.98 | Blaise Riebe | Beaverhead Co./Dillon (A) | | State A Track Meet |
| 40.04 | Slade Allen | Fairfield (B) | | State B Track Meet |
| 40.09 | Kodee Varner | Baker (B) | 11 | State B Track Meet |
| 40.12 | Mark Huntington | Butte (AA) | | State AA Track Meet |
| 40.27 | John Collins | Flathead (AA) | 12 | State AA Track Meet |
| 40.37 | Beau Berg | Helena Capital (AA) | | Western AA Divisional |
| 40.42 | Brady Baughman | Frenchtown (A) | 11 | State A Track Meet |
| 40.44 | Dylan Reynolds | Florence-Carlton (B) | 12 | State B Track Meet |
| 40.51 | Jay Owens | Missoula Big Sky (AA) | 10 | State AA Track Meet |
| 40.87 | Boone Helm | Broadwater/Townsend (B) | | State B Track Meet |
| 40.89 | James Stanton | Billings Central (A) | | State A Track Meet |
| 40.92 | CJ Edgmond | Laurel (A) | 11 | State A Track Meet |
| 40.93 | Hunter Morrical | Bozeman (AA) | | Eastern AA Divisional |
| 40.95 | Taylor Beld | Billings Skyview (AA) | 12 | Eastern AA Divisional |
| 41.02 | T.J. Harris | Huntley Project (B) | | Al Walker Memorial Invitational |
| 41.12 | Brian Sinrud | Helena Capital (AA) | 10 | State AA Track Meet |
| 41.26 | Kodiah Gimbel | Columbia Falls (A) | | State A Track Meet |
| 41.33 | Izaack Zier | Manhattan (B) | | State B Track Meet |
| 41.43 | Bo Descheemaeker | Fergus/Lewistown (A) | | Central A Divisional |
| 41.71 | Preston Schubert, | Thompson Falls (B) | 10 | Western B Divisional |
| 41.86 | Nick Propp | Missoula Sentinel (AA) | 12 | State AA Track Meet |
| 41.87 | Quinn Chamberlain | Helena Capital (AA) | | Western Montana Top 10 |
| 41.91 | Corbin Keaster | Belt (C) | | Northern C Divisional |
| 42.08 | Nathan Maughan | Fort Benton (C) | | Northern C Divisional |
| 42.44 | Adam Moore | Noxon (C) | | Western C Divisional |
| 42.75 | Jesse Sonntag | Saint Labre (B) | 12 | Southern C Divisional |
| 42.83 | Conner Rose | Shields Valley (C) | | Western C Divisional |
| 43.14 | Zach Ehly | Judith Gap-Moore (C) | | District 7C |