-- Instead of spending time at playgrounds, Arizona 4-year-old Hadlie Brechler is rock star, climbing on some of her state's most difficult mountains -- with the help of her parents, of course.
Hadlie began climbing when she was 1 year old, her father Jared Marvel said.
"I leaned up a sheet of plywood against the side of our house and put some rock holds on it and she started climbing," he said Saturday on "GMA."
The mother and daughter duo have amassed an online following thanks to their daring climbs. Photos show little Hadlie swinging from a harness and even clutching a ledge with her bare hands.
"I hear parents [say], 'Slow down! Don't climb that! Stay out of trees,'" Morgan Brechler said.
Marvel added, "And we spot her when she's climbing and it's very safe."
Morgan Brechler said that rock climbing has benefited Hadlie in more ways than just physically.
"I get to see her confidence build with every move that she makes," she noted.
Brechler and Marvel believe it's so safe that they even helped create the Born Wild Project to encourage other parents to embrace nature with their children.