| Glen Zirbel's efforts: | From | Age | Date | Finish Time |
|---|---|---|---|---|
| Hardrock 100 1999 | Iowa, US | 68 | Friday, July 9, 1999 | DNF |
| Hardrock 100 1998 | Iowa, US | 68 | Friday, July 10, 1998 | DNF |
| Hardrock 100 1997 | Iowa, US | 66 | Friday, July 11, 1997 | DNF |
| Hardrock 100 1994 | Iowa, US | 63 | Friday, July 8, 1994 | DNF |