I hiked to St. Mary's Glacier with a couple of friends.  It is a short fifteen or twenty minute hike from the parking lot.  It started off slow but eventually we found what was working.  The previous time I there, I caught some very nice Tiger Trout.  This time I had the camera and only got this one tiny Tiger, but a Tiger none the less.  Brookies were also taking my FBBH Pheasant tails and midge emergers.  Scuds in olive were working as well.  If you like the Dry Dropper method than I would tie on an Adams in size 22 to 24.  It is a fun and productive lake but the fish aren't real huge.  A 3 weight was my choice of rod.  A 9 foot Elkhorn made here in Colorado.  Good Luck and tight lines!!