An 18-month-old toddler who had wandered out of his house in Bradford sometime Monday was found safe by a Maine game warden.

The boy’s parents were sleeping after having worked an overnight shift Sunday. Near daylight Monday, the mother opened the door of the house to let out the family dog and it’s believed the door may have been left open, enabling the toddler to get out.

The father discovered the boy missing when he woke up at 1 p.m. Monday. After an initial search didn’t find the boy, the family called police.

Game wardens, Maine State Police troopers with dogs and a Maine Forest Service helicopter responded to the house after 2 p.m. at Isthmus Road off Route 221 in Bradford.

Game Warden Jim Fahey found the boy about half a mile away, behind the residence, just after 4 p.m., sleeping in a tire rut on a grassy road. The boy appeared to be in good health.

The case remains under investigation by the state police.