| Mark | Athlete | School | Year | Meet |
|---|
| 56.84 | Peyton Frame | Custer Co./Miles City (A) | 11 | Midland Roundtable Top 10 |
| 58.14 | Rachael Wilmot | Whitefish (A) | 12 | Western A Divisional |
| 58.48 | Macy Brandon | Havre (A) | 11 | Glendive Shriners Invitational |
| 59.07 | Kaitlyn Dantic | Laurel (A) | 12 | Midland Roundtable Top 10 |
| 59.45 | Blythe Armstrong | Fergus/Lewistown (A) | 11 | Eastern A Divisional |
| 59.55 | Annalise Lewis | Hamilton (A) | 10 | Nelson-Thomas ABC Meet |
| 1:00.72 | Heather Haskins | Frenchtown (A) | 12 | Nelson-Thomas ABC Meet |
| 1:00.80 | Shae Gooden | Frenchtown (A) | 12 | MCPS Invitational |
| 1:00.89 | Shaylee Weidow | Corvallis (A) | 12 | MCPS Invitational |
| 1:01.13 | Ryleigh Kleinke | Sidney (A) | 12 | Fairview HS Invite |
| 1:01.37 | Odessa Glade | Custer Co./Miles City (A) | 10 | Hardin SCAD #2 |
| 1:01.52 | Ginger Bergland | Whitefish (A) | 9 | Bigfork/Columbia Falls/Whitefish Tri |
| 1:01.93 | Amelia Stene | Polson (A) | 10 | Whitefish ARM Invitational |
| 1:01.94 | Ashley Andrews | Columbia Falls (A) | 11 | Bigfork/Columbia Falls/Whitefish Tri |