The robber ran out the door and disappeared, possibly cutting through an alley off the Washington Street bank.
Shepherdstown Police Chief Cecil Arnold said it was unknown where the robber went or if he had a vehicle waiting for him.
Immediately after the robbery was reported, police officers throughout Jefferson County established a cordon on the roads leading outside of town.
Two deputies set up a roadblock on W.Va. 230, one armed with a shotgun, the other with an M-14 rifle.
Initial reports had said the robber was armed with a submachine gun.
Based on the initial description of the robber, the deputies ordered one man from Idaho to pull his car over to the side of the road.
Seth Galli, 26, said it was just one more thing gone wrong on a bad day.
Galli had just left the bank apparently moments before the robbery. He was wearing a green jacket similar to one described by witnesses. He was in town to enroll for classes at the college.
A bank teller was brought to the scene and told West Virginia troopers that he was not the robber.
"I wasn't worried," Galli said. "I just figured it would end a typical day."
The robber was described as a white man, about 5 feet, 8 inches to 5 feet, 10 inches tall with a medium build, Arnold said.
He wore a green jacket, dark pants and white sneakers, he said.
Arnold said a description of the robber will be sent to area police agencies to see if it matches the description of any other robbers.
Arnold said he did not know when the last time a Shepherdstown bank had been robbed, if ever.
Police officers and Jefferson County sheriff's deputies walked through Shepherdstown, looking for any clues that may have been left by the robber.
A reserve deputy flew his helicopter over the town and surrounding roads.
Police searched for a dye pack that had been placed with the money into the bag. Officers turned over trash cans and plastic barrels in homes along Washington and New streets to see if the robber had stashed the money or weapon.
Police also went door to door through the neighborhood, asking residents if they saw anyone suspicious cutting through their yards.