NL200$ Fold the River ?

[Crashem]

Villain: 25/15/1,7/200 seems to be relatively solid

PokerStars No-Limit Hold'em, $2 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

saw flop|<font color="#C00000">saw showdown</font>

CO ($267.30)
Button ($125.90)
SB ($129.70)
Hero ($357.55)
UTG ($200)
MP ($239.50)

Preflop: Hero is BB with 6[img]/images/graemlins/heart.gif[/img], 4[img]/images/graemlins/heart.gif[/img].
<font color="#666666">1 fold</font>, <font color="#CC3333">MP raises to $7</font>, CO calls $7, <font color="#666666">2 folds</font>, Hero calls $5.

Flop: ($22) 4[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/diamond.gif[/img], 6[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets $20</font>, MP folds, CO calls $20.

Turn: ($62) 3[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $40</font>, CO calls $40.

River: ($142) A[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">CO bets $70</font>, Hero folds.

Final Pot: $212

I put him on AK here. Why should a solid opponent otherwise call on a ragged K high Flop all the way threw ? He might have KQ here also. The River bet looked just like a real "please call me type of bet".
Now that I review the hand it is really close. Thoughts appreciated ...

[FGators]

Who is villain?

Pot the turn. I'm not quick to put him on AK since he just smooth called preflop. A ton of people reraise AK preflop no matter what position.

I think its a solid river fold.