There's definitely a few folks running Grizzly with Shoshone thrown in for fun on their SUP's. I went with Matts about 2 weeks ago for 2 laps on Shoshone. A lot of swimming but he did clean maneater on the 2nd lap
Nice photos. Good spot for it.
Charlie McCarther has his own board now called the C-Mac. It has foot straps and Charlie can now roll on one. The only person I know that can do it so far. He is killing it on his SUP board these days.
We have been doing Shoshone to Glenwood on our Uli boards lately. Lots of fun and a heck of a workout. Kayakers pick it up quickly it seems as they know how to brace off the paddle blade. Its loads of fun for river running. I'm sure it is a sport that will take off on the rivers now as the new inflatable designs make them more durable to taking rock hits.