Surveillance video has been released showing the suspect.
The alleged assault happened last Thursday, July 16 around 10:30 a.m. on the Santa Gertrudis Creek Trail, underneath Winchester Road.
Deputies found a female with minor injuries who said she was sexually assaulted.
A similar incident occurred June 14 in the same area, when a woman was assaulted and her cellphone was stolen.
The investigation is ongoing. Anyone with information is asked to call Riverside County Sheriff's Department detectives at (951)696-3000.