Andrew Harrelson still has a few foggy memories of the day his parents came home with a woolly mammoth tusk strapped to the back of a four-wheeler.

"This big, old log-looking thing," recalled Harrelson, who was about 3 years old at the time, growing up in the Norton Sound village of White Mountain. "I had no clue what it was until they told me."

Andrew knew it must be important. His mother, Luann Harrelson, had spotted the 79-pound fossil that day in the gritty, strange-smelling muck of Fish River and posed her son for a Polaroid beside it.

That was 1992.

On Sunday, Andrew made a discovery of his own at precisely the same river bend just two miles outside the village.

Peppered across northern Alaska, tusks of the extinct species range in age from 12,000 to 400,000 years old and advertise for as much as $75 per pound on the resale market. Here is how a mother and son each made the discovery of a lifetime, 20 years and 10 feet apart.

A bend in the river

Once the site of an Inupiat fish camp, White Mountain is a community of 200 people about 60 miles from Nome. Every spring it balloons into an Iditarod Trail Sled Dog race checkpoint as dog teams park on the still-frozen Fish River.

Luann Harrelson grew up there. As a child, she said, villagers sometimes traveled to the river bend 2 miles from home to collect permafrost for ice cream.

"It would stink, like something was rotting in that mud," she said.

In the early 1990s, after Luann had begun dating her future husband, Daniel Harrelson, the couple went for a boat ride in search of trout. They anchored at the well-known bend where villagers had previously found mammoth teeth.

"I think at one point, thousands of years ago, it must have been a mud hole or something that animals got stuck in and then died in it," Daniel Harrelson said. "Everything froze in there and then slowly, over time, thaws out a little bit year by year."

With the fishing finished and their young daughter asleep in the boat, Luann's job was to hoist up the anchor. As she prepared to leave she saw an unusual shape about 10 feet below the surface. A piece of wood maybe. But it looked too smooth. There were no knots or branches.

Curious and suspecting that they had found a fossil, Daniel motored the family home and returned for a better look. Leaning halfway out of his boat, he fished the blue-black tusk free using a rake and a rope.

"Within an hour, he came back with the tusk on the back of a four-wheeler and said, 'Hey, look at your piece of wood,' " Luann said.

On a tight budget, the young family hoped to fetch a big payday. Daniel Harrelson flew it to Anchorage, where the manager of a local shop had agreed to sell it. Too bad they hadn't found it a week earlier, the store manager said. Actor Steven Seagal had just been in Anchorage and spent thousands on mammoth fossils.

For weeks, the couple heard nothing. Eventually Daniel hounded the manager, who said someone had stolen the tusk from his garage. He paid the skeptical couple just $1,500.

"We were very disappointed," Luann said. "But, you know, we figured that was a good little fishing trip for us to come back with that."

History repeats

Old photos show that the tusk Luann and Daniel found was long and tightly curled. Experts said it likely belonged to a mammoth -- the official state fossil of Alaska -- rather than a mastodon. An older species present during interglacial periods, mastodons have straighter, elephant-like tusks.

It's unclear how many mammoth tusks have been discovered in Alaska, although far more are reported in the northern half of the state, said Robert King, Alaska state archaeologist for the Bureau of Land Management. "Partly because there's a lot of placer mining there," he said.

Most of Alaska is public land and it's against the law to remove mammoth fossils from state and federal property without a permit, he said. But unlike elephant ivory, mammoth fossils discovered on private land can be legally traded under some circumstances. A BLM spokeswoman said the area surrounding White Mountain and the Fish River is privately held.

Just how old the mammoth tusks are is also a mystery.

The last glacial period in Alaska was about 18,000 years ago, said retired Quarternary paleontologist Dale Guthrie of Fairbanks. While some mammoths survived longer on islands, mainland mammoths had died off by about 12,000 years ago, he said.

"The (White Mountain) tusks could be that young or they could be when mammoths first arrived here, which is 300,000 to 400,000 years ago," Guthrie said. "You'd have to radio carbon date it to see its age."

Today, Daniel Harrelson is the village public safety officer for White Mountain. His son Andrew works in Nome as a mechanic for the state but said he returns as often as possible to fish and hunt near his childhood home.

After catching just a single silver salmon in two hours on one such trip along the Fish River on Sunday morning, Andrew Harrelson decided to look for tusks, he said. His fiancee and the couple's daughters, 2-year-old Hannah and 11-month-old Danielle, rode along.

Slowing the boat to half-throttle, Andrew arrived at the bend where his mother spotted her find about 22 years before. Almost immediately he saw the base of a tusk, covered by a stump.

"No way!" his fiancee said. She looked on the other side of the boat and saw what appeared to be tip of the fossil.

Like his father a generation before him, Andrew boated his family back to the village. "We couldn't keep our eye on the tusk and keep our eyes on the kids at the same time," he said.

He returned with a relative. After several tries they used a 10-pound anchor to pry the stump away.

Shocked by the size, Andrew measured the fossil at about 12 feet long. To weigh it, he held the tusk with the help of two people and stepped on a bathroom scale. Their unscientific estimate: 162 pounds.

Word of the discovery spread, and prospective buyers began ringing Andrew's cellphone, he said. The same store manager who lost Daniel and Luann's tusk 20 years before now wants to buy Andrew's fossil too, Daniel said.

Get a firm price before you sell, the father advised. Meantime, the Harrelsons like to think about the size of the animal the massive fossil was attached to thousands of years ago, Daniel said.

Andy's youngest daughter turns 1 year old next month, and the couple is thinking of buying their first home in Nome, one of the most expensive housing markets in Alaska.