WOW - I gotta get down there! I've fished the Bighorn in Montana and had a great time - but I really love the small waters where you have to actively stalk the fish - you spook them and they are gone.
Here are the kinds of waters that I'm used to from out in the Black Hills - although this is the exception and not the rule since there are normally trees overhead that I have to cast under, which is when my 6' 2wt comes in handy:
Here is a sample of the fish that are out there - this was from a small pond created by a dam on Spearfish Creek
And this pig was from another dam on Little Spearfish Creek
All were caught on zebra midge nymphs fished low - fish were hanging in the vegetation...
Just thinking about it makes me want to drive down to Broken Bow / Illinois River right now!