3/6 - weird river spot oop vs. donk

[DCal Zone]

Villain is 1-tabling and seems like a pretty standard weakish donk. No stats on him and haven't played any pots against him. Have only seen him limping a bunch.

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

Button ($557.60)
DCal Zone ($594)
BB ($257)
UTG ($522.35)
MP ($910.95)
CO ($640)

Preflop: DCal Zone is SB with A[img]/images/graemlins/diamond.gif[/img], T[img]/images/graemlins/club.gif[/img].
<font color="#666666">3 folds</font>, Button calls $6, <font color="#CC3333">DCal Zone raises to $30</font>, <font color="#666666">1 fold</font>, Button calls $24.

Flop: ($66) 9[img]/images/graemlins/spade.gif[/img], 8[img]/images/graemlins/heart.gif[/img], T[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">DCal Zone bets $48</font>, Button calls $48.

Turn: ($162) K[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
DCal Zone checks, <font color="#CC3333">Button bets $78</font>, DCal Zone calls $78.

River: ($318) 4[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>

I am fairly certain that most players would raise any hand that I'm losing to on the flop. I could have been outdrawn on the turn by a 2-pair or a flush draw, but I believe that I am still ahead enough of the time that would make folding the turn bad. I think betting, c/c, and c/f are all reasonable options on the river.