On a 300,000-mile journey, you can expect a bump or two in the road.

But as the Maitland family wended their way down the Natchez Trace Parkway — a historic route spanning Alabama, Mississippi and Tennessee — they seemed to hit the most dreaded of bumps.

Something emerged from the weeds and scampered under the space between their pickup truck and the camper it was towing.

"When my husband got out, it wasn't a woodchuck," Cheri Maitland tells MNN.

But rather, a black dog. Remarkably, unharmed. But of no fixed address.

A park ranger would later tell them she was probably dumped in the area.

And so, some six years later, she is their dog — aptly named Natchez — and a living breathing souvenir from a most legendary journey.

A black dog sitting on the ground. She was just 6 weeks old when the Maitland family first saw her. (Photo: Maitland Family)

"We have a park puppy," husband Jim Maitland explains from the family home in Jackson, Michigan.

"When she's bad," their daughter Jameson chimes in, "We call her Natchez Trace Parkway."

"Her head is too small and her ears are crooked," Cheri adds. "And she's the best dog ever."

But more than a mere souvenir, Natchez is now family.

And for the Maitlands, that's ultimately what their eight-year odyssey was all about.

Pickup truck and camper Their caravan — a pickup truck and a camper — was too small to hold onto grudges. (Photo: Maitland Family)

Jim, Cheri and their children, 16-year-old Jameson and 15-year-old Gerald,recently wrapped up a journey that took them to 418 national parks and units — a designation for battlefield sites, memorials and national trails.

Their inspiration? A documentary series called "The National Parks: America's Best Idea." In it, filmmakers Ken Burns and Dayton Duncan chart a six-episode exploration of some of the country's most iconic natural and historic treasures — from Yosemite to the Everglades to the Alaskan Arctic. The series proved just the spark for the Maitlands, who already harbored an abiding love for America's parks.

Along the way, they set a Guinness World Record as the first family to reach every national park and unit in the country.

They also welcomed more family into the fold. Like a couple of exchange students who joined them for a stretch.

"We picked them up from the airport, we stuck them in the fifth wheel and we took them to the total solar eclipse in Nebraska," Cheri says.

Kids witnessing eclipse. The Maitlands had barely picked up the students at the airport before they were all taking in the Great American Eclipse of 2017. (Photo: Maitland Family)

At the time, Taiga, the Japanese student, could hardly speak English.

"He kept showing his arm to tell us he had goosebumps," Cheri explains. "He never experienced anything like that.

"In 10 months, we were able to give those kids 30 states and 73 national park units."

Kids in a field of flowers. On a journey this long, leg-stretching stops were mandatory. (Photo: Maitland Family)

The Maitlands also learned a lot about the family they were born with.

"It was very … interesting," Jameson says. "We had ups and downs. But everything always seemed to flatten out. We all can't hold grudges because we're stuck somewhere together."

And, of course, they learned a whole lot about the land that is their home.

"You can see beautiful pictures," Jim says. "But until you walk through the caves, or until you hike over that mountain, it's just not the same."

"Booker T. Washington's home. Booker T. Washington's birthplace…" he muses. "The kids got to walk in the exact same place that Daniel Boone walked. You're walking in the same places. You're seeing where the history actually happened."

"You walk into places where people died in battle. You hear their stories ..."

"And you can't forget them," Cheri finishes his sentence .

"No history book can give you that," Jim adds.

That's not to say every stop was a standout. When asked about some of the low lights of the trip, Gerald chimes in without hesitation: "Mount Rushmore."

"It did what it wanted to do," he explains. "It was a tourist attraction. But ... it was faces carved into a wall."

"Which is an incredible feat," his dad Jim reminds. "But when you walk in, it's T-shirt shops and all that kind of stuff."

"We should have watched it from the parking lot," Cheri concurs. "Once you walked in, it felt like you were at Disney World without the rides."

Kids sitting under an arch at Capitol Reef National Park The kids soaked up the scene at Capitol Reef National Park in Utah. (Photo: Maitland Family)

The Maitlands kept careful notes not only of the places they visited, but also what they learned from them. Sometimes, it was a simple entry about the ranger they met. Or what they did in that place.

They also managed to volunteer more than 1,000 hours at their home park, River Raisin National Battlefield Park in Michigan.

And just about everywhere, they collected a lot of trash.

"We always tried to leave it better than when we got there," Cheri says.

But with the U.S. government shutdown leaving parks largely un-staffed, that became an increasing challenge towards the end of their journey.

"One thing that's made me very angry," Gerald says, "Is that the parks have been shut down, and people are going into the civil war battlefields and metal detecting."

Indeed, when you rob the past, you also steal from the future.

"Why would you do that?" Gerald asks. "That's history. That's powerful. It's a sacred place."

Kids jumping into the air. They were inspired by 'The National Parks: America's Best Idea,' a documentary by Ken Burns and Dayton Duncan. (Photo: Maitland Family)

The journey helped Gerald come to a decision about his career. He wants to study water waste management.

"Everyone needs clean water," he says.

And his sister Jameson, who always wanted to study speech pathology, is now thinking about becoming a marine biologist.

"I want to help save the animals," she says. "And get rid of all the plastic."

And all of a sudden, because one family decided to go far back in time — towing an old camper along the way — the future is brighter for us all.

Especially for a certain black dog with an undersized head and an ever-twirling tail.

A girl hugging a dog Natchez practically flung herself into the arms of the Maitlands. (Photo: Maitland Family)

You can read more about the Maitland family's incredible journey — and bask in more incredible pictures — on their Facebook page.

This family's 8-year odyssey brought them to 418 national sites across America
From Hawaii to Alaska, this Michigan family has visited 418 national sites.