MADISON, Wis. — Three teenage boys got lost in a labyrinthine abandoned iron mine in southeastern Wisconsin for hours, spending the night huddled together against the cold before rescuers found them Monday afternoon.

The boys — Tate Rose and Zachary Heron, both 16, and 15-year-old Samuel Lein — were reported missing about 9:45 p.m. Sunday, authorities said at a news conference.

About 2 a.m. Monday, police found their bikes off a road near an entrance to the mine, Dodge County Sheriff Dale Schmidt said.

Firefighters and rescue teams from multiple agencies began searching the mine, which Schmidt described as a ‘‘vast maze’’ of tunnels that goes on for four miles.

Searchers’ efforts were hampered by water that was as deep as 8 feet in some tunnels as well as a number of cave-ins. The search involved 100 people, dogs, and thermal imaging devices.

Rescuers led by a state Department of Natural Resources specialist who was familiar with the mine finally discovered a footprint early Monday afternoon and heard the boys yelling for help.

The boys weren’t hurt aside from scratches, Schmidt said.

‘‘It was a very sad situation that turned into a very joyous one,’’ Schmidt said.

Associated Press