RCMP Cpl. Holly Marks said the abduction and assault happened at 12:15 p.m. PT on June 22.
The girl was waiting for a bus at 42nd Avenue and 204th Street, when the man drove up in a small, newer model, silver hatchback.
"The suspect pulled up in a vehicle her and ordered her to get in. She was terrified and did as he said. Once inside the vehicle, he produced a large knife," Marks said in a written statement.
He then drove to the parking lot of a church in the 21200 block of 56 Avenue, and sexually assaulted her.
"He then drove her to the Langley bus loop at Logan and Glover and released her without further incident," Marks said.
The 16-year-old has since worked with police and a sketch artist to come up with a composite sketch of what her assaulter looked like.
The suspect is Caucasian, around 50 years old, and is 6 feet tall. He has a heavy build, pale blue eyes, and is balding with greyish-blond hair. At the time of the assault, he had a full beard and was wearing bluish-grey shirt and pants and sunglasses.