Among those arrested, Shamsher has confessed that he had assaulted the girl sexually, the SDM said, adding that all the four have been sent to Pauri Jail.
The victim, who belongs to the forest-dwelling Gujjar tribe, is a native of Sigaddisrote settlement near Kotdwara.
She was allegedly abducted by the accused on January 2 and found six days later from Gadarpur in Udham Singh Nagar district.
However, the mother of the victim has said in her complaint that eight persons were involved in abducting the girl at gun-point.
Medical report of the girl confirmed sexual assault, Nayab Tehsildar Chhawan Singh said.
The incident occurred in the Laldhang Range of Lansdawen Forest Division in Pauri district and fell under the purview of the revenue police as rural policing is done by revenue officials in Uttarakhand.