The bones were found by a beach walker Thursday morning, said Milford Police.
At first, responding officers could not tell if the bones were human or animal and sent crime scene investigators to inspect the find.
After an inspection of the bones, police have learned the bones are animal, said Milford Police Officer Mike DeVito.
A further examination determined they were pig bones, officials said.
Silver Sands State Park consists of 297-acres of beach and woods and is home to a 14-acre bird sanctuary on Charles Island.
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