The victim, a 24-year-old local man, suffered a broken leg and ankle in the incident which occurred next to the children’s play park on Harrogate Road, at around 6am on Friday 22 July 2011.
The victim was punched, kicked and pushed over a wall during the assault.
Police are appealing to anyone who witnessed the incident to come forward with information.
PC Jereme Hillcoat, of Ripon police, said:
This was a nasty attack which left the victim requiring hospital treatment.
I am appealing to anyone who witnessed the assault to contact the police or Crimestoppers with any information that can help the investigation.
Anyone who can help the police with their enquiries is urged to contact PC Jereme Hillcoat, of Ripon police, on 0845 60 60 24 7, quoting reference number 12110129680.
Alternatively, Crimestoppers can be contacted anonymously on 0800 555 111.