The highest point in the US is Denali (Mt. McKinley), which is also the highest point in North America. I understand that you have to be in decent shape to climb it, but that it's not (bearing weather in mind) a particularly difficult climb. Mt. Borah, the highest point in Idaho, is much the same.

Since I am not in decent shape I flew around McKinley in a small plane and ignored Borah (although it IS a pretty mountain).