MileSplit Staff May 08, 2026 PRO See the rest of this article Access the complete article with MileSplit PRO. Subscribe to keep reading Already a subscriber? Log in. Improvement Rankings: Top South Dakota Girls 400m marks compared to their season’s best performances from 2025. Most Improved - 400 Meter Dash Comparing 2026 season to 2025 season Rank Improved Athlete/Team Class 2025 PR 2026 PR 1 -12.11 Justice Sovell Sully Buttes High School 2030 1:24.94 1:12.83 2 -9.69 Josie Sovell Sully Buttes High School 2030 1:21.01 1:11.32 3 -9.14 Olivia Hanson Viborg High School 2027 1:24.65 1:15.51 4 -7.50 Sage Martz Centerville High School 2029 1:09.27 1:01.77 5 -6.38 Hannah Masterson Scotland High School 2028 1:24.03 1:17.65 6 -6.34 ...