Depending on how ambitious your group is, you can start in Whistler Village, or drive up to the Stonebridge trailhead. From the Stonebridge trailhead, you will take the Darwin's trail climb up to the Rainbow flank trail. This is considered to be a normal climb by Whistler standards, but you haven't even started the climb to the alpine!

Ride east along the flank trail until you get to the "Into the Mystic" trailhead - a large wooden arch with a metal sign marks the entrance. From here, it is a 9km climb up steep switchbacks. Though not a technical climb, it will take every ounce of energy you have! Be sure to bring snacks and lunch. 

Once you reach the top of "Into the Mystic", you will have the option of several out and back trails that are purely scenic alpine riding. 

To complete the loop continue your climb up "On the Rocks" up and over towards the summit of Mount Sproatt. When you reach the trailhead of "Lord of the Squirrels", this is your queue to get ready for one of the best descents of your life. Not overly technical, with lots of flow, this decent winds its way all the way back down to the flank trail. 

From the flank trail, you can return the same way that you climbed, or return via some of the more technical Whistler Westside trails.