I notice that quite a few people are finding this site looking for information on the Ruby Crest Trail. Hopefully the beta here has been useful!
Be advised that we have a HUGE snowpack this year... it's hanging on late... and the high passes could be snow covered later than usual. We're supposed to have hot weather next week and may finally see some melt-off, but right now (9 June) the snowpack at the Lamoille Canyon trailhead is still deeper than I am tall.
If you're planning on doing this trip with a horse you might want to consider waiting until mid-to-late July, in order to give the snow a chance to melt off. Otherwise, you risk injuring your horse and tearing the hell out of the trail. Obviously I'm no oracle, but based on my observations from having lived here most of my life I think that's probably your best plan.
I'll keep an eye out for you and will post up as things melt out a bit more.