Police said the search for any sign of Nicole Morin — including possibly her body — is a follow-up to a tip that came after they released a video re-enactment in July of her disappearance as an eight year old.
"We have information that leads us to a thorough ground search up here," Insp. Gerry Cashman told The Canadian Press from Springwater Township.
"We're looking for any evidence whatsoever in relation to Nicole being here if she was here at all after she went missing in July of 1985."
Police said the dogs would be capable of picking up a scent if the girl met with foul play and was possibly buried in the area.
Provincial police, who are leading the search, came up empty handed after previously searching the area near Barrie following a call two days after her disappearance.
While finding anything now is a long shot, Cashman said it was important to do due diligence in light of the new call from the same person.
"It continues to bother the individual — they had the knowledge of what they thought they knew," he said.
"We don't know. We want to close all the loops. We're taking that investigative risk and coming up here...to make sure we don't leave something unturned."
In all, 40 officers and support staff are taking part in a search that will likely end Thursday if nothing is found.
At the time of her disappearance, Nicole was living with her parents in a west-end apartment building. On the morning of July 30, 1985, she said goodbye to her mom with plans to meet a friend in the lobby to go swimming. She was never seen again.
The ensuing search has been one of the largest and longest investigations ever done by Toronto police, who said they have been receiving tips from the public regularly for three decades.
Police, who are still treating the disappearance as a missing-person's case, have never arrested anyone in the case. They also ruled out any family involvement.
"We want to try to solve every case we have," Cashman said.
"If there's anything we can do to solve this mystery, we will do it."