How cold does it get there at night....if it gets cold, like Illinois, then he is dead by morning.....follow his blood, the exact trail you seen him on, and he will go about 100 yards before his final nap...if it gets real cold at night, go about 7am tommorrow and recover him....once the temps drop, and he has lost blood, and bile, then his body temp goes down as well, and he dies from shock...its natures way of ending his suffering....the shot you made, it happens to all of us, congrads in advance, I feel you will find him in the morning..........al