This route is a grand tour of the Bridgers. Very intimidating to see the route in its entirety from West Bozeman or Belgrade. Foothills trail was indeed "created by a demon" to inflict maximum vert and pain on its travelers, but it's incredibly beautiful, especially during the June bloom.
I dropped water and snacks at Ross pass the day before the effort to provide two restock opportunities, which are well-spaced within the context of the day.
Some snow on the climb to Sac pass which obscured the trail for a short bit, otherwise was able to stay true to the route. Some short bouts of post-holing and tricky navigation around snow on the ridge, but those sections were brief.
Great day all in all. I was moving slow on the downhills from Sac to the M. Somebody moving swifter on those portions could certainly take this under 10 hours no problemo. Best part of the route = no shuttle required to Fairy Lake!