The incident happened in the Scotton Road area of Catterick Garrison between 1am and 1.30am (before the clocks went back) on Sunday, October 29.
The victim, a woman aged in her 20s, reported being grabbed from behind and sexually assaulted by an unknown man.
She bravely fought him off after biting his upper left arm.
The victim is receiving specialist support from the police and partners agencies.
Police say extensive enquiries have been ongoing since the incident to locate the suspect, including house to house, CCTV and forensic examinations.
As well as information about the suspect with the bite on his upper left arm, officers are appealing for witnesses and people with relevant dashcam and doorbell footage in the area from around the time of the incident.
Detective Inspector Matthew Wilkinson, from Hambleton and Richmond CID, said: “This is a very concerning incident, and we are doing everything we can to support the brave victim while we track down the suspect.
“He is likely to have a noticeable bite mark on his upper left arm.
“If you think you know who this person could be or have any information or footage that could assist the investigation, please make a report without delay to either the police or to Crimestoppers anonymously.”
The Catterick Garrison Neighbourhood Policing Team is carrying out reassurance patrols in the area to deal with community concerns.
If you can help the investigation, please email email@example.com or call North Yorkshire Police on 101, select option 2, and ask for Matthew Wilkinson. Please leave a message and he will come back to you as soon as possible.
If you would prefer to remain anonymously, contact Crimestoppers on 0800 555 111 or make an online report.
Please quote reference 12230207079 when providing details.