Digging up his front yard to make way for a new pond -- that was the plan.

"For quite awhile we've been toying with the idea of making it nicer," Rich Schneider said.

But what Schneider and his family uncovered in the process, proves there was life in Portland, long before the Schneider's ever got here.

"The excavator came out and started working on it and all of a sudden he came across a large bone," Schneider said.

Bones -- which a paleontologist from the University of Michigan says --are the remains of an ancient mastodon.

"The second thing we found is the front leg and then we just kept finding small pieces of bone, a rib and a tusk," Schneider said.

The Schneider's front yard has turned into an archaeological dig, their garage has become a sort of make-shift museum.

"Everyone wants to come over and see them," Schneider said, "It's quite amazing."

The Schneider's don't know how big this animal was when it was alive, but its left femur bone stands about four feet tall. A University of Michigan scientist estimate this animal died when it was in its 30s between 10,000 and 13,000 years ago.

"It's unbelievable to think one, 13,000 years ago someone was walking around, and two, an animal of that size was walking around here," Schneider said. "It's pretty phenomenal."

The Schneider's plan to donate the bones to the University of Michigan. Until then, the family is still digging hoping to find more pieces of history.

"In the past few days we've gotten a paleontology 101 lesson," he said.

Newsten tried to get in touch with a local scientist, but was unsuccessful.

The Schneider's say Dr. Dan Fisher -- the paleontologist from the University of Michigan that came to their house Tuesday -- believes early humans killed the animal for meat, then kept it submerged in a small lake that used to be there to preserve it. It was kind of like an early refrigeration system and it stayed that way for 13,000 years.