| Mark | Athlete | School | Year | Meet |
|---|
| 44.20 | Tavy Findon | Billings Senior (AA) | 11 | State AA |
| 45.39 | Ashley McElmurry | Missoula Sentinel (AA) | 11 | State AA |
| 45.59 | Adrian Schnee | Glacier (AA) | 12 | Western AA Divisional |
| 45.87 | Lucy Corbett | Bozeman (AA) | 12 | State AA |
| 46.34 | Joylynn Glidewell | Missoula Big Sky (AA) | 10 | Western Top 10 Meet |
| 47.03 | Kailee Stoppel | Billings West (AA) | 12 | Midland Roundtable Top 10 |
| 47.03 | Mayjia Horst | Bozeman (AA) | 10 | Eastern AA Divisional |
| 47.35 | Abigail Harmon | Helena Capital (AA) | 12 | Western AA Divisional |
| 47.41 | Lauren Bingham | Missoula Sentinel (AA) | 12 | Western AA Divisional |
| 47.52 | Gianna Migliaccio | Missoula Big Sky (AA) | 10 | Charlo/Deer Lodge/Drummond/Frenchtown |
| 47.77 | Aubry Grame | Glacier (AA) | 10 | State AA |
| 48.07 | Fallon Parker | Belgrade (AA) | 11 | John Tomich Invitational |
| 48.11 | Audrey McElmurry | Missoula Sentinel (AA) | 9 | Western Top 10 Meet |
| 48.21 | Melissa Moreni | Helena Capital (AA) | 10 | Western AA Divisional |
| 48.25 | Macy Mayer | Bozeman (AA) | 9 | BWH/BSR/Bozeman Triangular |
| 48.34 | Skyleigh Thompson | Flathead (AA) | 9 | Western AA Divisional |