A woman walking on a gravel path near the Petaluma River was robbed and stabbed in the face Monday night by a man who appeared to be intoxicated, police said.The woman was walking near Water Street when the man approached her around 8:20 p.m., Sgt. Marty Frye said. The man demanded money, and when she refused he stabbed her in the face with a knife and pushed her to the ground, Frye said. The man then forcibly removed money from the woman’s pants pocket and ran away.The woman went to a nearby business for help and was taken to a hospital for treatment of a cut on her face and a contusion to the back of her head, Frye said. None of her injuries were considered life-threatening, police said.Police searched the area but did not find the man, Frye said. The suspect is a heavyset white male adult, about 50 years old and clean-shaven with dark hair. He was wearing a plaid shirt and blue jeans, Frye said. Anyone with information about the incident is asked to call Petaluma police at (707) 778-4372.