I just did the IceBox480 this past weekend in River Falls, WI which was a fun race. You basically run as far as you can in 8 hours (480 min) starting off on a 7 mile looped trail. At 2 PM you have to decide if you want to attempt another 7 mile loop and finish before the 3:30 finish time (if you don't finish the loop the miles don't count), or switch to a 1 mile loop and run as many of those as you want. I did 6 full loops (42 miles) and didn't feel like doing a mile loop in the remaining minutes for 15th place overall. It's a pretty fun but challenging course and I'd recommend it as a low key end of season race...or for me it's kind of kick-starting 2018 training.

The Canyons 100K (CA) in April will be my first trail ultra of 2018 and its a WS qualifier (must be under 18 hours to qualify)