one of the best senior discounts is the "Golden Age Passport"
its a lifrtime pass to any National park,TVA project.bureu of reclamation,corps of engineer project,and some other federal places
it costs $10 for a lifetime pass,and you must be 62 to get it
we have used it many times,It worked great at Crater Lake when we came home from the Nationals in Portland
you just hand them the card instead of money,they hand it back with all the free brochures ,and say"Thank you ,have a nice visit"
they are availible at any ranger station or national park