County Sheriff's officials said.
Scanner traffic around 9:50 a.m. Monday reported that the man entered the bank wearing a mask and dark clothing with only parts of hands exposed. He was armed with a "revolver-type" weapon and approached one of the bank's two tellers. The teller handed an unknown amount of cash over to the suspect, and he loaded it into a black backpack.
Authorities at the scene said that they were unsure whether the man was wearing a cloth ski mask or a hard, plastic mask. Scanner traffic reported the man allegedly fled on foot on Topaz Avenue from the bank, but deputies at the scene said it was unclear if the suspect fled on foot or in a vehicle.
Sheriff's deputies and detectives were on scene at 10 a.m. and were reviewing surveillance video and photos as they searched for the suspect.
No injuries were reported.
The incident is under investigation, and Sheriff's officials said they would not be releasing any further information. The bank was closed at 11 a.m. and will remain closed while authorities investigate the incident.
Anyone with information about the suspect or the incident is urged to call the Hesperia Sheriff's Station at 760-947-1500. Anonymous tips can be left on the WeTip Hotline at 800-78-CRIME or www.wetip.com.