I've caught all thee native species in CO, all four in WY, westslopes in ID, and Lahontans in NV. I know the CDOW takes some heat over their CR/greenback stockings but you need to research Behnke's position on this.
If you want greenbacks, try Roaring River - a very healthy population and the further you hike the better the fishing. For CR cutts, try Timber Creek and for a real experience hike into the meadow area below Timber Lake (~5 miles). For Rio Grandes: Lake Fork of Conejos, Cascade Creek, or Prospect/Treasure Creek.
If you want to catch brookies, the best brookie stream I've fished anywhere in the US is Tonahutu Creek along the Green Mtn trail in RMNP...brook trout on every drift!