Ismith: Pardon me for not noticing your posting (query) sooner.
It may seem to some that I miss-spoke or miss-identified the "West Slope Cutthroat" - it is the custom hereabouts to refer to the West Slope Cutthroats caught "east" of the Continental Divide as "East Slope Cutthroat".
It is probably incorrect or an inaccuracy but it is what it is and is what many of us do.

Link: https://www.fws.gov/fisheries/freshwater-fish-of-america/westslope_cutthroat_trout.html

Whether they are east of the "slope" or west of it they are fun to catch and a beautiful trout indeed.
By the way the lake where I caught "said fish" was just a few hundred feet east of the Continental Divide (Idaho/Montana border).
I hope that "trout" survived the winter up there and gives me a chance at him again this summer! I'll bet he will be pushing 20" maybe 21".
Hold into the wind
VarmintGuy