| John Korfmacher's efforts: | From | Age | Date | Finish Time |
|---|---|---|---|---|
| Red Feather Trail Jamboree 2025 50 Mile | Colorado, US | 60 | Friday, September 26, 2025 | 12:17:20.00 |
| Red Feather Trail Jamboree 2024 Half (Half Marathon) | Colorado, US | 59 | Sunday, September 22, 2024 | 02:17:48.00 |
| 2017 Golden Gate Dirty 30 (50K) | Colorado, US | 51 | Saturday, June 3, 2017 | 07:02:30.50 |