| Mark | Athlete | School | Year | Meet |
|---|
| 42.86 | Liz Harper | Missoula Sentinel (AA) | 11 | Western AA Divisional |
| 43.22 | Tess Brenneman | Flathead (AA) | 12 | Western AA Divisional |
| 44.78 | Morgan Sulser | Billings Senior (AA) | 10 | State AA Track Meet |
| 45.47 | Allison Morrison | Helena (AA) | 12 | Western AA Divisional |
| 45.47 | Kiera Bulluck | Fergus/Lewistown (A) | 12 | Central A Divisional |
| 45.86 | Lakyn Connors | Corvallis (A) | 11 | Southwestern A Divisional |
| 46.14 | Lexy Boschee | Glacier (AA) | 12 | Whitefish A.R.M. Invitational |
| 46.18 | Shelby Erdahl | Belgrade (AA) | 12 | Gallatin Valley Invitational |
| 46.69 | Amanda Foley | Whitefish (A) | 12 | Western Montana Top 10 |
| 46.98 | Hailey Phillips | Plains (B) | 9 | Western B Divisional |
| 47.14 | Alyssa Espinoza | Billings West (AA) | 11 | Billings City Meet |
| 47.17 | Hailey Gellner | Billings Skyview (AA) | 10 | Billings Invitational |
| 47.32 | Brianna Gray | Park City (C) | 10 | Southern C Divisional |
| 47.36 | Kayla Hanson | Chinook (C) | 12 | State C Track Meet |
| 47.39 | Melissa Lynn | Dawson Co./Glendive (A) | 12 | Eastern A Divisional |
| 47.44 | Kinsey Schwers | Harlowton (C) | 10 | Southern C Divisional |
| 47.51 | Natalie Zimmer | Missoula Big Sky (AA) | 12 | Western AA Divisional |
| 47.59 | Holly Anderson | Beaverhead Co./Dillon (A) | 9 | Beaverhead Booster Meet |
| 47.60 | Tori Nickol | Helena Capital (AA) | 12 | Western AA Divisional |
| 47.64 | Jada Scheffelmaer | Fergus/Lewistown (A) | 11 | Central A Divisional |
| 47.71 | Kwyn Johnson | Flathead (AA) | 11 | Libby-Flathead Dual |
| 47.78 | Keely Ehmann | Darby (C) | 9 | Western C Divisional |
| 47.79 | Megan Hawkins | Park/Livingston (A) | 10 | Central A Divisional |
| 47.83 | Bridger Rice | Savage (C) | 12 | State C Track Meet |
| 47.86 | Brianna Olson | Missoula Sentinel (AA) | 11 | Western AA Divisional |
| 47.95 | Jordan Dreessen | Billings Senior (AA) | 12 | 5-5 Billings West Triangular |
| 48.12 | Summit Parcell | Seeley-Swan (C) | 12 | 13C Districts |
| 48.12 | Hope Reid | Thompson Falls (B) | 11 | Columbia Falls Invitational |
| 48.18 | Melissa Hofer | Melstone (C) | 12 | State C Track Meet |
| 48.18 | Marissa Sokoloski | Wibaux (C) | 11 | Southern C Divisional |
| 48.19 | Kaytlin Halle | Manhattan Christian (C) | 12 | Western C Divisional |
| 48.25 | Tori Weyand | Billings West (AA) | 12 | Eastern AA Divisional |
| 48.27 | Aspen Runkel | Charlo (C) | 10 | State C Track Meet |
| 48.34 | Courtney Carl | Missoula Big Sky (AA) | 9 | Western AA Divisional |
| 48.48 | Debra Griebel | Glasgow (B) | 11 | Northern B Divisional |
| 48.61 | Martha Dembek | Winnett-Grass Range (C) | 11 | Northern C Divisional |
| 48.68 | Reedie Spencer | Cut Bank (B) | 12 | Northern B Divisional |
| 48.69 | Hayley Moen | Sweet Grass Co./Big Timber (B) | 11 | Stillwater Invitational |
| 48.83 | Lexi Prevost | Sidney (A) | 10 | State A Track Meet |
| 48.91 | Mattie Mazur | Flathead (AA) | 10 | Optimist Track Meet |
| 48.92 | Marisa Sokoloski | Wibaux (C) | 11 | Bowman County Booster Meet |
| 48.93 | Rhiannon Sturgess | Flathead (AA) | 10 | Western AA Divisional |
| 48.93 | Bethany Norby | Billings Senior (AA) | | State A Track Meet |
| 48.95 | Alison Lunde | Flathead (AA) | 12 | Western AA Divisional |
| 48.95 | Terra McDowell | Billings Senior (AA) | 12 | State AA Track Meet |