“Arctic Frog” Endurance Run is a beginner’s Ultra marathon. This scenic course features a trilogy of pavement, wooded and crushed limestone trails that runs North and South of Des Plaines River (DPR) and Northwest Casey Trails. Make NO mistake- it will NOT be a “gimme” with a few challenges in stow (rolling hills) but fair! What's more, if lucky-this northern Chicago suburbia turns into a "Winter Wonderland" come December each year making it a unique running experience for anyone that haven’t tried running in the cold winter months!

Upcoming Races

Dec 14 2019
50 KM
Multiple Loop Course
2 Elevation Rating
Rolling, ~2500 feet in 50 miles
2 Surface Rating
Mostly groomed trail or dirt roads


50 KM View course top times

Date Finishers Top Result Top Result (F)
12/01/18 72 4:24:33 4:00:47
12/02/17 105 3:15:43 4:42:16
12/03/16 79 3:24:34 4:14:05
12/05/15 110 3:59:41 4:11:08
12/06/14 52 4:09:00 4:12:01
We try to keep the most accurate information about this race, but changes do happen. Always visit the official race website for the most up to date information.
Denali 135
  • Jul 4, 2020
  • Paxson, AK
135 Miles