The woman was walking on the trail near the intersection of South Jackson Street and Riverside Street around 2:20 p.m. March 24th when she saw a man walk out from a wooded area and start running after her.
According to a Janesville Police Department news release, the woman screamed and ran away from the man, who police described as white, in his late-40s, 6 feet tall and 150 pounds.
The man ran off after the woman screamed, authorities said, and was last seen running east on the trail. He was wearing a black jacket, tan hooded sweatshirt and dark jeans.
Authorities are asking anyone with information to call Janesville Crimestoppers.