Revised 11.15.21
| CLASS | DISPLACEMENT | LAPS** | |
| 1 | AMA Pro | 350-450cc 4-Stk* | 18+2 |
| 2 | Pro-Am | 201-450cc 4-Stk | 13+2 |
| 3 | Pro Sport | 201cc-Open | 6 |
| 4 | Open B | 201cc-Open | 4 |
| 5 | Open C | 201cc-Open | 4 |
| 6 | 450 A | 201-450cc 4-Stk | 5 |
| 7 | 450 B | 201-450cc 4-Stk | 4 |
| 8 | 450 C | 201-450cc 4-Stk | 4 |
| 9 | Production A | 201-450cc 4-Stk* | 5 |
| 10 | Production B | 201-450cc 4-Stk* | 4 |
| 11 | Production C | 201-450cc 4-Stk* | 4 |
| 12 | Production Stock B/C | 201-450cc 2-Stk/4-Stk* | 4 |
| 13 | College (16-24) | Sportsman: 201cc-Open | 4 |
| 14 | Junior 25+ | 201cc-Open | 5 |
| 15 | Veteran 30+A/B | Sportsman: 201cc-Open | 4 |
| 16 | Veteran 30+ C | 201cc-Open | 4 |
| 17 | Senior 40+ A/B | 201cc-Open | 4 |
| 18 | Senior 40+ C | 201cc-Open | 4 |
| 19 | Masters 50+ | 201cc-Open | 4 |
| 20 | WMX | 201-450cc 4-Stk | 5 |
| 21 | Women (15+) | 201-450cc 4-Stk | 4 |
| 15 yr old: 201-250cc 4-Stk |
| YOUTH CLASSES: Age is based on the rider's age on January 1 | |||
| 22 | Youth All-Star (14-17) | 91-200cc 2-Stk, 91-250cc 4-Stk | 5 |
| 201-400cc 4-Stk* | |||
| 23 | 250 Mod (13-15) | 91-200cc 2-Stk; 91-250cc 4-Stk | 4 |
| 201-400cc 4-Stk* | |||
| 12 yr old: 71-112cc 2-Stk; 75-150cc 4-Stk | |||
| 24 | Schoolboy Sr. (13-17) | 91-200cc 2-Stk; 91-250cc 4-Stk; | 4 |
| 201-400cc 4-Stk* | |||
| 25 | Schoolboy Jr. (12-15) | 71-112cc 2-Stk; 75-150cc 4-Stk | 4 |
| 91-200cc 2-Stk*; 91-300cc 4-Stk* | |||
| 12 yr old: 71-112cc 2-Stk; 75-150cc 4-Stk | |||
| 26 | Super Mini (12-15) | 71-112cc 2-Stk; 75-150cc 4-Stk | 4 |
| 27 | 125 (8-15) | 90-125cc 4-Stk* | 4 |
| 28 | Schoolgirl (13-17) | 91-200cc 2-Stk; 91-250cc 4-Stk | 4 |
| 201-400cc 4-Stk* | |||
| 12 yr old: 71-112cc 2-Stk; 75-150cc 4-Stk | |||
| 29 | Girls (8-13) | 70-90cc 2-Stk; | 4 |
| 125cc 4-Stk* | |||
| 30 | 90 Open (8-13) | 71-90cc 2-Stk; 125cc 4-Stk | 4 |
| 31 | 90 Automatic (8-13) | 71-90cc 2-Stk; 125cc 4-Stk* | 4 |
| Automatic/CVT/Single Speed | |||
| 32 | 90 Shifter (8-13) | 71-90cc 2-Stk; 125cc 4-Stk; Shifter | 4 |
| 33 | 70 Open (6-11) | 51-70cc; | 4 |
| 125cc 4-Stk* | |||
| 34 | 70 Automatic (6-11) | 51-70cc*; Automatic/CVT/Single Speed | 4 |
| 35 | 70 Shifter (6-11) | 51-70cc; Shifter | 4 |
| 125cc 4-Stk* | |||
| 36 | 50 Open (4-8) | 0-50cc | 4 |
| 37 | 50 CVT (4-8) | 0-50cc*; Belt-Drive | 4 |
| 38 | 50 Automatic (4-6) | 0-50cc; Automatic/CVT/Single Speed | 3 |
| 0-50cc; Automatic/CVT/Single Speed | 3 | ||
*Production Rule Applies
**Laps are 'weather permitting'. Pro/Pro-Am reference is to time, then laps.