The Utah Cuttslam website is a great resource. I've always assumed the the trout in one of my favorite mountain creeks were Bonneville cutthroat because I knew they were natives. But there are native Colorado cutties in the northwestern streams of Utah.
And they are gorgeous fish!
Look at the bright slashes and crimson cheeks on these trout.
The Colorado cutthroat are a joy to catch because they are plentiful and readily take dries.