I found good color in the Rutt Nat Forest.west of Yampa in the flat top wilderness.No gas engines allowed in the wilderness.But good panning and sluicing.(Watch out for the big cats,there sneaky)
The Arkansas River north of the Royal Gorge is very good for corse Gold.
Down close to Ft.Carson you might try thee Canon City area or Silverton. But watch you don't jump any claims.
Kurt