GEOFF BENNETT: He goes by Grey Beard, and earlier this week, he set an incredible record, becoming the oldest person to ever complete the Appalachian trail.

Amna has the story.

AMNA NAWAZ: It's not as simple as putting one foot in front of the other.

Sometimes, it's climbing down an old tree stump, thwarting a river, and then taking a well-earned rest on the 2,198-mile-long trail.

DALE SANDERS, Appalachian Trail Record Setter: I am 91, so I'm blazing new grounds for hiking long distance like this.

No one in the 90s has ever threw hiked or section-hiked the Appalachian trail.

Only two people in the 80s have done it.

It's not a sport normally participated in by older people.

But maybe they will start coming out now after I'm setting the example.

Woo!

AMNA NAWAZ: Dale Sanders completed what's known as the Appalachian Trail Thru-Hike, all of the trail sections from Springer Mountain in Georgia to Mount Katahdin in Maine, in any order within a year.

MAN: I was so sad.

I thought maybe I'd never meet this legend.

You're a legend for me.

AMNA NAWAZ: Along the way, in spite of the 71 times he says he fell, he inspired other hikers and was inspired himself.

DALE SANDERS: One of the things that surprised me is how quickly the public caught on that it's -- and started following me.

How many people were encouraged and embraced by my efforts at 91 to try and hike this trail?

That's really a bit inspiring to me at the same time.

AMNA NAWAZ: This isn't the first time Sanders has made this trek and earned this record.

He first did it at the age of 82.

DALE SANDERS: There's a huge, huge difference between hiking the trail at 82 years old or at 91, huge difference.

But it is possible, because I'm proving that.

AMNA NAWAZ: Grey Beard ended his journey on this Maine mountaintop on Monday, bringing to life words widely attributed to Ingrid Bergman, comparing growing old to climbing a mountain: "You get a little out of breath, but the view is much better."