On October 31, 2021 I ran the Herriman Lake Trails Loop. I started at 3:01pm and ran clockwise. It was snowing off and on. The trails are pretty technical and make it hard to get into a good rhythm. I got back to the trailhead at 4:53pm. I didn't see anyone else. There were no faster times on Strava.
I've been sitting on this one for a couple weeks. I wasn't sure if it should be an FKT route since it isn't a named trail exactly, but it is a distinct trail system far away from other trail systems. The trails are well maintained for how little use they get. There are a few places where the trail runs along a ridge next to a couple lakes. If there were a few less trees in the way you would have a much better view. All in all its a beautiful trail if you're looking for solitude.