He says he got out of his car to look at a bird on the causeway when he spotted something near a large drainpipe.
“I looked down there thinking, what’s a cow doing laying on the road?
“And then I realized what it was.”
He says he has seen bigger crocs in the Mary River but he did not want to risk getting too close.
“He’s fairly big. I wouldn’t like him hanging off me, I can tell you that much.”
He estimates the croc to be about as long as his car, which was four meters (12 feet) in length.
“What I was really concerned about was when they take off and get that tail flapping,” he said.
“The wife’s car, which I was in at the time, might have had a nice big dint across the side.”
Last week Parks and Wildlife officers trapped a two-meter (6 feet) crocodile at the dam.
Visitors are advised not to walk on the causeway because of the risk posed by crocs.
Source: ABC News