AA At 100NL

[grando]

Villain is 30/13/1 after not-so-many hands - just seems like a calling station. How do I play this river?

Poker Room skin
No Limit Holdem Ring game
Blinds: $0.50/$1
4 players
Converter

Stack sizes:
Hero: $128.90
Button: $91.80
SB: $55.90
BB: $18.50

Pre-flop: (4 players) Hero is UTG with A[img]/images/graemlins/club.gif[/img] A[img]/images/graemlins/spade.gif[/img]
<font color="#cc0000">Hero raises to $4</font>, Button calls, 2 folds.

Flop: 6[img]/images/graemlins/club.gif[/img] 5[img]/images/graemlins/heart.gif[/img] 4[img]/images/graemlins/heart.gif[/img] ($9.5, 2 players)
<font color="#cc0000">Hero bets $9</font>, Button calls.

Turn: T[img]/images/graemlins/club.gif[/img] ($27.5, 2 players)
<font color="#cc0000">Hero bets $22</font>, Button calls.

River: 7[img]/images/graemlins/club.gif[/img] ($71.5, 2 players)
Hero ???