Nick Clark posted the route:
The trailhead for Round is 7 or 8 miles (maybe more) west of Loveland on Hwy 34. Two or 3 miles west of the Big Thompson Narrows, there is a pull-off to the left. This leads to the parking lot for Round. Route goes from trail map to big cairn at Summit: 4.8 miles & 3,000'. 95% singletrack.
Note: The Round Mountain Trail ascends Sheep Mountain (confusing!)
There is a Strava segment for this route, but it seems to end ~30sec shy of the actual summit cairn. FKT times are to the cairn.
I'm about to do this. Is the time out and back, or summit?
Thanks for posting this FKT! I went out and did this with a buddy just for a weekend romp. Was a good time (and humbling to compare our time to the current FKT); and we probably wouldn't have found this idea had it not been posted here.