Vancouver police say a man held up the Palm Beach Tan, 14415 S.E. Mill Plain Blvd., about 8:50 p.m. on Tuesday.
He displayed a handgun to the clerk and fled the store on foot with an undisclosed amount of cash, Vancouver Police spokeswoman Kim Kap said.
The suspect is described as a white man in his 30s or 40s, about 5-feet 10-inches and 180 pounds and unshaven with a goatee. He was wearing a hooded black and gray jacket, jeans and a baseball.
Officers, including one with a police dog, searched the area but were unable to find the suspect.
Anyone with information on this suspect is asked to call the Vancouver Police Department. Their tip line is (360) 487-7399.