Beginning at the Mirror Lake parking, this loop takes you first a few miles of vertical gain on single track and across several boulder fields. Depending on the time of year there may be snow covering a few of these. The trail lis a little tricky to follow if you don't keep an eye out for the wooden posts marking it. This trail levels out as it wraps around the back of peak before the last 0.9 mile boulder field climb. The view at the peak is nothing less than breathe taking, you can see Brown's peak to the northeast, Elk mountain to the west, and Steamboat is in the range far to the south. Prepare yourself for the descent about 50-100 yards north of the peak the descent begins, prepare your knees. It's a very technical down hill but a lot of fun full of tight switch backs. Once off of the initial descent turn right at the sign for the single track that will carry you back to the Mirror Lake parking lot to finish. This run is one of the most popular hikes by far and one of the most scenic views in the area.
I am attempting the Medicine Bow Peak Loop FKT tomorrow, October 8th, 2020. Wanted to share to let everyone know.
For future attempts, here's the best way to navigate the Mirror Lake Picnic Area near the end of the route: heading counter-clockwise around the Medicine Bow Peak loop, you'll encounter a fork in the trail just before you reach the paved picnic area roads. Take the left fork straight down to the road and then follow the road in the direction of traffic to the paved trail on the right. This paved trail runs adjacent to Hwy 130 and takes you back to the start.
Correction to the comment above: I meant clockwise around the Med Bow Peak loop.
As of 7-23-21, Derk Lyford appears to have the current FKT with an elapsed time of 1:10:52. Derk may still submit the FKT to the website, but I figured I would post this for anyone looking to attempt the route in the near future. Here's a link to his effort. Also, I think it's worth mentioning that Derk started and ended at the West Lake Marie Trailhead, instead of using the vague social trail just south of the actual trailhead that others have used to start previous attempts. I think Derk's approach to the start is preferable because it eliminates erosion and the perpetuation of social trails.