The 17-year-old was found outside the George Hotel in Market Place at around 4am on Saturday.
Police are now today (Thursday) appealing for witnesses as she remains in a critical condition in hospital.
A North Yorkshire Police spokesperson said: "Police are investigating to help determine the full circumstances surrounding the incident and conducting enquiries in the area.
"Anyone who was in the area at the time or who has any information which could assist our investigation is urged to contact us.
"Please call North Yorkshire Police on 101, select option 2 and ask for York Serious Crime Team. You can also call Crimestoppers anonymously on 0800 555 111.
"Please quote reference number 12170024089 when passing on information."