16th Annual Rock CF Rivers Half Marathon
Sun, Mar 21, 2027 · in 5 months Grosse Ile, MI
Half marathon5K
Race website & registration Your chances
Where would you finish?
Enter your race pace or connect Strava, and raceIQ compares you with this race's past finishers in your age group and gender.
See your predicted place7th
of ~140
Age group
Finish times
From the 2026 results.
| Distance | Finishers | Winner | Top 5% | Top 25% | Median |
|---|---|---|---|---|---|
| Half marathon | 672 | 1:03:19 | 1:23:30 | 1:41:43 | 1:57:09 |
| 5K | 399 | 17:24 | 21:58 | 29:35 | 35:35 |
Field strength
5KLocal
Faster up front than 45% of the 5K races we track, based on 788 finishers over 2 editions.
Half marathonVery competitive
Faster up front than 97% of the half marathon races we track, based on 1,374 finishers over 2 editions.
Finishers by year
| Year | Half marathon | 5K |
|---|---|---|
| 2026 | 672 | 399 |
| 2025 | 702 | 389 |
Upcoming races nearby
All races in Michigan