ENDANGERED SPECIES: Rare Nev. butterfly approved for federal protection Jessica Estepa, E&E reporter Published: Friday, September 20, 2013 A rare butterfly found only in the mountains west of Las Vegas was approved yesterday for endangered species protections. Please subscribe to Greenwire to read the full story. Username: Password: Forgot your access codes? Recover them. Not a subscriber? Sign up for a trial. Ready to subscribe? Click here.