The 18-year-old was attacked near the Ben Nevis Holiday Park, Camaghael, Fort William, on Friday evening.
Officers are checking for any relevant CCTV footage from that area to help them trace the person responsible.
Sergeant Brian Heriot said: “From enquiries carried out so far we have established there were several people in the area that evening. I am appealing to those local residents and members of the public who were there to contact us. Any small piece of information could prove significant as we work to establish the person responsible for this attack. If anyone has dash cam footage, please check it as that too could aid our enquiries.”
Anyone with information is asked to call Police Scotland via 101, quoting incident number 0955 of 19 June, 2021. Alternatively, please call Crimestoppers on 0800 555 111 where you can give your information anonymously.