| Low Country Fat Tire Freaks | Goose Creek | Club |
| Lowcountry Biking | Charleston Low Country | Club |
| Lowelifes Respectable Citizens' Club | Southern California | Club |
| Lower Arkansas Mountain Bike Association | Cañon City | Club |
| Macomb MTBC | Macomb | Club |
| Mad River Riders | Mad river valley, waitsfield | Club |
| Magic City MTB | Minot | Club |
| Magnolia Bike Club | Gloucester | Club |
| Maine Mountain Bike Association | | Club |
| MAMBA-Moscow Area Mountain bike Assosiation | Moscow Mountain | Club |
| Mankato Area Mountain Bikers (MAMB) | Mankato | Club |
| Marin County Bicycle Coalition | San Francisco Bay Area | Club |
| Markham Park Trail Building Fund (MPTBF) | Sunrise | Club |
| MECCA Mt. Bike Club | Emery County | Club |
| Medicine Wheel | Pikes Peak Region | Club |
| Mendocino Coast Cyclists | Fort Bragg | Club |
| Mere Mortals Mountain Bike Club | Sunnyvale | Club |
| Methow Evergreen MTB | Methow Valley | Club |
| Methow Valley Sport Trails Association (MVSTA) | Winthrop | Club |
| Metro Detroit Mountain Bikers | Metro Detroit | Club |
| Metro Mountain Bikers | Metro Milwaukee Area | Club |
| Miami Hawks MTB Club | miami | Club |
| Miami Valley Mountain Bike Association (MVMBA) | Dayton | Club |
| Michigan Mountain BIking Association | | Club |
| Michigan Red Riders | Michigan | Race Team |
