Thinnish river spot vs donk

[aislephive]

Villain is 70/2 over a reasonable sample of a couple hundred hands. Standard massive PP donk. Preflop, flop, and turn are pretty obvious. I'm unsure of the best river play, though. He is bad but I'm not sure how much of his range can call a river bet, and it's possible he is playing a better two pair hand or something in this manner. Then again, he is 70/2 and pretty unpredictable. Thoughts?

Party Poker, $2/$4 NL Hold'em Cash Game, 6 Players
LeggoPoker Hand History Converter

CO: $286
Hero (BTN): $427.60
SB: $81.40
BB: $88
UTG: $394.80
MP: $655.20

Pre-Flop: 8[img]/images/graemlins/heart.gif[/img] 9[img]/images/graemlins/heart.gif[/img] dealt to Hero (BTN)
<font color="red">UTG raises to $14</font>, MP folds, CO calls $14, Hero calls $14, 2 folds

Flop: ($48) 8[img]/images/graemlins/spade.gif[/img] 9[img]/images/graemlins/spade.gif[/img] A[img]/images/graemlins/spade.gif[/img] (3 Players)
UTG checks, CO checks, <font color="red">Hero bets $36</font>, UTG folds, CO calls $36

Turn: ($120) 4[img]/images/graemlins/diamond.gif[/img] (2 Players)
CO checks, <font color="red">Hero bets $90</font>, CO calls $90

River: ($300) 7[img]/images/graemlins/diamond.gif[/img] (2 Players)
CO checks, Hero ??? (villain has $150 ish behind)