K-9 units were called in so the robber's direction of travel away from the bank could be tracked, police said.
The man was described as white, 5 feet 7 or 8 inches tall, about 35 years old, with a full, blond-colored beard.
He was wearing a yellow sweatshirt and a New York Yankees ball cap, faded blue jeans and Fila sneakers.
Police said the robber produced a note demanding money. No weapon was displayed but police said tellers reported he said he had a weapon.
No one was injured. It wasn't known if any money was obtained by the robber. police said.
Roofers working across the street said they saw nothing and heard nothing. When told there had been a robbery, one of the workers vented his frustration.
"I've got to work for my money,'' said Harry Shrader. "They gotta work for theirs, too.''
This was the 10th bank robbery in Washington County this year.
On Monday afternoon, a customer who watched a masked man rob the American Trust Bank in Williamsport followed the robber out of the building and gave investigators detailed information that led to two arrests minutes later.
Two brothers, formerly of Hancock, were charged in connection with that robbery.
David Scott Knapp, 19, and Jacob Paul Knapp, 20, both of Route 1, Box 200-17, Inwood, W.Va., were charged with armed robbery, robbery, theft and conspiracy to commit robbery.
Both were still being held this morning in lieu of $75,000 bond each, jail officials said.