There are two events held by Jack Lake Silent Sports Association:

• Crazy Eights WEMS Mountain Bike Race- (10 hour - 6 hour - 3 hour)
• Jack Lake Ultra Eights Trail Run (64 mile - 10k - 5k distances). Rucking classification for each distance.

Check out their pages on here for more information.

Antigo Swim Club, also, hosts the MK Triathlon and Splash & Dash in the summer.