Neil Bernstein was last seen on Friday, Feb. 17 on the Maryland side of Great Falls Park in Potomac, according to a spokesperson from the Montgomery County Police Department.
Great Falls Park is a popular national park that stretches through Maryland and Virginia.
Family and police are growing concerned for Bernstein's welfare as time goes on.
Bernstein is described as being 5-foot-9 and he weighed around 190 pounds at the time of his disappearance, according to officials. He has short grey and brown hair and green eyes.
Police are asking anyone who visited and took photos or videos of the Great Falls Park area off MacAruther Boulevard during the time Bernstein went missing to contact them at 1-866-455-TIPS (8477).
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