Workers installing a new sewer on an Indiana farm made a mammoth discovery this week — 13,000-year-old mastodon bones.

The Schepman family of Seymour first thought cow or chicken remains had been found during the renovations, but when they saw a giant tusk and 4-foot-long thigh bones, they realized the beast was much larger and more ancient.

“It’s amazing to think about something this large roaming around this area,” Joe Schepman told the Seymour Tribune.

“The weight of them is unbelievable,” he said while holding a bone. “When the tusks were on the animal, they were about 9 feet long if you can imagine that.”

An ancient member of the elephant family, scientists estimate the forest-dwelling creatures roamed North and Central America before they became extinct more than 10,000 years ago, likely due to overhunting by tribes.

An expert from the Indiana State Museum studied the bones and confirmed the remains belong to a male mastodon weighing 12,000 pounds who would have been aged between 40 and 50 when he died 13,000 years ago.

“It was a very big animal, and it’s amazing to think about what was here before us and how we don’t think anything about it,” son Brad Schepman said.

While it is rare to find so many bones from the same animal, museum expert Ron Richards told the Seymour Tribune that mastodon bones are found in Indiana up to twice a year.

“People find them interesting because they were real, they were here and they’re every bit as much a Hoosier as I am,” Richards said.

An American mastodon unearthed in 1998 named “Fred” is already an iconic fixture at the Indiana State Museum.

The Schepman family have decided to donate the remains to the museum so they could be “enjoyed by everyone.”

“It would be so cool for a kid from here to go to the museum in Indianapolis and see these bones and the tusk and know they were found in their hometown,” Brad Schepman said.

This story originally appeared in the New York Post.