i also pretty muchly agree with everything previously stated. you have an ace high, that bet on the flop wasnt bad but you should have taken the info. he gave you with the call. my guess is he made a pair or is on a draw. i think hes got you beat but if hes gonna let you see a free card with all his checks then id take it here after all if he doesnt end up nothing(unlikely) then you know youve got him beat with the ace high.
i also agree that with that bet on the river you open yourself up to a re-raise.