He probably back tracked. Start where the trail ended and work it backwards looking for sign of where he back tracked and then left his trail. I have seen this several times when good blood trails just ended. They really didn't end the deer just back tracked on his own trail(natural instinct) and then left the trail again. Did you listen closely and if so did you here him crash or splashing through the swamp. He might have headed for a high ground hideaway out in the swamp. Those are my two best guesses. Good Luck!

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