Mountains cover 70 percent of the Korean peninsula, and in South Korea, an estimated 1 in 3 Koreans goes hiking more than once a month. Over the past few decades, hiking has become way more than a weekend activity. It's part of the Korean national identity.

Across the Pacific Ocean in Southern California, second- and even third-generation children of Korean immigrants are keeping alive and well a tradition that connects them to their ancestral homeland.

L.A.'s Griffith Park comprises 4,000 acres where dusty trails weave up and down the bone-dry scrubland. Every day, but especially on early weekend mornings, you'll find the trails packed with Korean hikers rocking hiking poles, face masks, and enormous visors to block the Southern California sun. There are Korean-Americans of all ages using the trails, but a good number of those hard-core hikers are in their 50s and older, immigrants from South Korea.

"You see grandparents, pushing their walkers up, walking with their canes," says 26-year-old Moonyoung Ko, a second-generation Korean-American who grew up hiking in Southern California with her parents and recently took NPR's Shereen Marisol Meraji along for a walk in the woods.

One of Ko's favorite short treks in Griffith Park is the Amir's Garden trail. It starts so close to the I-5 Freeway that you can hear the hum of traffic, and it offers a peaceful and verdant oasis at its end. There, you can take a breather and cool off on a bench in Amir's Garden before hiking on or heading down. It was named for an Iranian immigrant who visited Griffith Park regularly. After a devastating fire in 1971, the late Amir Dialameh brought plants up to this spot, one by one, to create the lush landscape.

It's an immigrant story Ko loves, and one of the reasons she keeps coming back. Her parents are also immigrants; her father left South Korea in 1978 and her mother joined him a few years later. Ko says when they weren't working to keep their Orange County dry cleaning business afloat, they were hiking or camping with their three daughters. It gave them a break, not just from the long hours at work but from their struggle to understand English and American culture.

"My parents sacrificed a lot for us to be here," says Ko. "Nature was their only solace. It was one of those places where they could go where you didn't feel isolated."

She says trips into the mountains jogged her parents' memories of home. Pine trees would elicit a story from her father about steaming New Year's rice cakes with pine needles. Her mother would stop and point out flowers along the trail, saying things like, " 'I know this flower. We used to take those petals and use it to dye our fingernails,' " Ko recalls. "It was kind of them recollecting their childhood and sharing it with us."

Ko was 4 the last time she visited South Korea but knows her parents are from a mountainous region called Gwangwon-do with a lake that's close to the ocean. Family vacations were always camping excursions up and down the California coast, and she's certain it was her parents' way of taking her back to their home country.

Five thousand miles away, you can exit a subway station in Seoul, turn a corner and be on a trail up rocky Inwangsan, one of the half-dozen mountains in or near the South Korean capital.

"It has one of the clearest views of the entire city, and you can also see old fortress walls along the trail," says Kang Seok-bong. He keeps a day job as an eyewear store owner. But every weekend he picks a peak and guides a group on a morning hike. He's better-known to hikers around here as Kang Gyver, a play on the name of the iconic '80s TV character MacGyver.

"If hiking sticks break, bags, cellphones, what have you, I fix it. I tend to fix things just in the nick of time," says Kang.

When Kang Gyver learns that Korean-Americans in places like Los Angeles are trying to keep up the hiking tradition, he wonders about topographic differences.

"In L.A., it's probably pretty different than hiking in the Korean mountains with your kids," Kang says.

Speaking of gear, the hiking culture here means a huge boon to outfitters, because no South Korean goes hiking without wearing an entire North Face catalog's worth of gear. We're talking sun sleeves, hats, neck guards, hiking poles — even for short, one-hour hikes. NPR's Elise Hu recently joined a hiking group that Lee Geun-rye meets up with on many mornings.

"People who like hiking here, they also enjoy the preparation process. It's probably a little strange and not understandable because we have so much stuff," Lee says.

So it's hard to call this just hiking. It's more like hiking plus plus. And for many South Koreans in their 40s and 50s, it's as much about socializing as it is about nature and exercise. Case in point: Every 20 minutes along the hike, the group stops to snack and drink booze — most often it's makgeoli, a fermented rice drink that's best served chilled and provides a good buzz.

When you finally reach Inwangsan's peak, the achievement means more libation and food with friends, with an even better view. There's so much collapsible gear packed that everyone has a handy hammock for a quick post-lunch snooze at the summit. American Peter Beck, who joins Kang Gyver most weekends, sums up the experience.

"These guys don't mess around," he says. "This is hard core."