Not until today. Carol and I are exploring Idaho's scenic byways and have landed in Island Park, on the Henry's Fork of the Snake River. I've read stories of the fantastic fish here and how hard they can be to catch. Now I can vouch for the first but not yet the second. Perhaps it's the early season, but even as a first-time fisher on this river I managed to net three nice rainbows (17"-19"), and I hooked several others.
The water in front of our hotel room (after several days in campgrounds, it was time for a shower) is wide and shallow, much like I remember the Madison River in MT being. So, finding fish means finding small slots and rocks. My approach was to start moving directly across the river, casting as I went. I found good and bad water and fish where you'd expect. On my four-weight rod, these strong and heavy fish were a challenge to land in the fast current of mid-river.
Even this early in the season, there are a good number of people on the river, but they come and go, so I never felt crowded. It may be that other sections of the river are busier, avoiding this section because I heard that releases of water from the Island Park Reservoir have had the river here going up and down daily. That works for me.