Let me re-state for emphasis:
DO NOT CHECK YOUR CAMERA IN CHECKED BAGGAGE. CARRY IT ON THE PLANE WITH YOU.
DO NOT CHECK YOUR CAMERA IN CHECKED BAGGAGE. CARRY IT ON THE PLANE WITH YOU.
DO NOT CHECK YOUR CAMERA IN CHECKED BAGGAGE. CARRY IT ON THE PLANE WITH YOU.
DO NOT CHECK YOUR CAMERA IN CHECKED BAGGAGE. CARRY IT ON THE PLANE WITH YOU.
DO NOT CHECK YOUR CAMERA IN CHECKED BAGGAGE. CARRY IT ON THE PLANE WITH YOU.

If for some reason you cannot carry it on with you, send it ahead to your destination via FedEx or DHL or some such courier that works for you. Putting a camera in checked baggage is tantamount to approaching a stranger on the street and asking them to watch it for you for the next twelve hours.

That said, I'd take the 80mm if you must take only one lens. I agree with the sentiment that out there, in the Sierras and Death Valley, the lens that works best is the longest.