The terrified youngster was bundled into a car by the man and driven to a dark field – but then saved by chance after the attacker was disturbed by passersby.
The 14-year-old victim was abducted as she walked along Crossley Lane in Mirfield and driven to a dark field at Hartshead.
He dragged her from the car on Hartshead Lane and subjected her to a terrifying ordeal.
But two people were in the field and when the man realised he was in danger of being rumbled, he escaped.
The attack happened at 6pm last Sunday and police are specifically appealing for the two people in the field or area at the time to contact them as they believe they may hold vital clues which could lead them to the attacker.
A West Yorkshire Police spokesman said: “We still need these two people to contact us as they may be able to assist our inquiries.”
The schoolgirl was taken to hospital, but was not hurt.
The attacker, whose motives are thought to be sexual, had a distinctive pig-shaped nose and big lips. He may walk with a limp or walk in a peculiar way and spoke with a local accent.
He drove a blue people carrier and is white, aged between 40 and 50 and slim with grey/blond short hair which appeared patchy.
He is thought to have been wearing an Adidas cap, a jacket and either blue or black tracksuit bottoms.
He was also wore a balaclava-type face covering when the attack took place and was seen to drive the vehicle wearing the mask.
Anyone who saw anything suspicious or recognises the description of the attacker should contact Det Sgt Simon Leek or Det Insp Paul Harrison on 0845 6060606 or the incident room on 01274 373642.
Alternatively, call Crimestoppers anonymously on 0800 555 111.