She was wearing black jeans, a blue Superman T-shirt, a long black winter coat and black boots. The teen is about 5-foot-3 and weighs 98 pounds with shoulder length brown hair and blue eyes. She also was wearing glasses.
According to police, Courtney was going to a neighbor's house, but she never made it. At about 9 p.m. she was reported missing.
Several reports indicate Courtney and Cambridge may have met on Skype.
Police Chief Michael Rasmussen said local police, city employees and others searched for the missing teen. Dogs also were brought out Sunday night to look for the girl in the wooded areas around the neighborhood.