| Mark | Athlete | School | Year | Meet |
|---|
| 44.07 | Madilyn Todorovich | Helena (AA) | 12 | Skor Dekam Invite |
| 44.54 | Alivia Rinehart | Flathead (AA) | 12 | Western AA Divisional |
| 45.36 | Delainey Engen | Billings West (AA) | 12 | Midland Roundtable Top 10 |
| 45.58 | Scarlet Harris | Great Falls (AA) | 10 | Great Falls Optimist Club Invitational |
| 46.06 | Nya Myers | Missoula Big Sky (AA) | 10 | Western AA Divisional |
| 46.41 | Carmen Eddy | Glacier (AA) | 12 | Great Falls Optimist Club Invitational |
| 46.45 | Hazel Bishop | Helena (AA) | 11 | Great Falls/Helena Dual |
| 46.71 | Addison Brisendine | Glacier (AA) | 9 | Western AA Divisional |
| 47.27 | Avery Stulc | Billings Senior (AA) | 9 | Eastern AA Divisional |
| 47.49 | Phoenix Hyland | Missoula Sentinel (AA) | 10 | Glacier/Sentinel Dual |
| 47.60 | Emmery Schmidt | Glacier (AA) | 12 | Russ Plicher Western Top 10 |
| 47.63 | Aizalyn Flaten | Great Falls (AA) | 11 | Great Falls Optimist Club Invitational |
| 47.65 | Addison Roush | Helena (AA) | 12 | Skor Dekam Invite |
| 48.12 | Isabella Grutsch | Missoula Big Sky (AA) | 12 | Big Sky/Butte Dual |
| 48.21 | June Lay | Helena Capital (AA) | 11 | Helena Crosstown Meet |
| 48.22 | Cadence Graham | Butte (AA) | 10 | Big Sky/Butte Dual |
| 48.30 | Gracelee Banna | Missoula Big Sky (AA) | 12 | Missoula "Greg Rice" City Meet |
| 48.63 | Claire Townsend | Billings West (AA) | 10 | Midland Roundtable Top 10 |
| 48.73 | Brooke Howlett | Helena Capital (AA) | 10 | Helena Crosstown Meet |
| 48.80 | Emme Burckley | Billings Senior (AA) | 11 | Eastern AA Divisional |
| 48.82 | Talyn Draayer | Billings West (AA) | 10 | Billings City Meet |