A man carrying a black revolver robbed the Bank of Marin at 23 Reed Blvd. in Mill Valley at about 11:45 a.m., Marin County sheriff's Sgt. Debra Barry said.
The robber was described as white or Hispanic, 40 to 45 years old, 5 feet 7 inches tall, with shoulder-length black hair that is believed to be a wig, Barry said.
He was wearing a brown suit-jacket, a white shirt with a red collar, blue jeans, black gloves and silver-rimmed glasses, Barry said.
He was carrying a black satchel and ran through the Strawberry Village Shopping Center afterward, Barry said.
In the second case, a bald, white man in his 50s robbed the Bank of Marin at 368 Ignacio Blvd. in Novato at about 12:45 p.m., Novato police Lt. John McCarthy said.
The man was wearing a surgical mask and a green jersey, McCarthy said.
Investigators have not yet said whether they believe the robberies are connected.