The Issy Alps has 4 unique routes to test your endurance. Each of the four routes can be stitched together to form longer routes.
50k starts at Mailbox Peak and ends at Little Si offering roughly 13K of total of elevation climb/loss.
100k continues off where 50k stops and traverses over Rattlesnake Mountain and Tiger Mountain ending at Tiger mt Highpoint TH.
An alternate (but much tougher) 100k course is an out and back of the 50k course offering a staggering 26K of total elevation climb/loss AKA “The Hard 100”
Finally the 100m distance covers the original 100k and does a lollipop loop via Squak and Cougar mountain ending at Tiger mt Highpoint TH.
Below are the maps needed to cover all of the distances listed here.