It turned out to be a piece of railroad equipment, police said.
The call came in from the tracks along Piermont Road near Riveredge Road shortly before 9 a.m., Capt. Michael deMoncada said.
Tenafly police considered the item suspicious enough to notify the Bergen County Sheriff's Bomb Squad, which just so happened to be conducting a weekly training exercise.
A CSX representative also was summoned to the scene and identified it as part of train signal equipment, deMoncada said.
"It was likely unearthed after the recent storm had flooded the area around the railroad tracks," the captain said.
Piermont Road was reopened once the item was deemed harmless, he said.
Click here to follow Daily Voice Hackensack and receive free news updates.