(CNN) - As a child, Ruth Hebert would run on the beach at the edge of the Pacific and look to the horizon knowing her father was out there, somewhere.
Growing up, she knew the word "Korea" before she even understood what it meant.
"I'd heard that word since before I could talk," she told CNN. "It was just part of our life."
Her father, Karle Seydel, was 24 when he left his wife, daughter and months-old son in Seattle, Washington to join the eventually hundreds of thousands of United States troops sent to the Korean Peninsula to fight in a bloody conflict which, almost 70 years later, has still not officially ended.
The Korean War broke out 68 years ago this month, when North Korean tanks and troops crossed the 38th parallel on June 25, 1950, as part of an "all out offensive" against South Korea.
The remains of thousands of US soldiers are still in North Korea, despite decades of effort by families and the US military to repatriate them.
Following his meeting with North Korean leader Kim Jong Un in Singapore this month, US President Donald Trump said the remains of hundreds of soldiers will be handed over. The first set of remains landed in South Korea on July 27, where they were greeted by a United Nations Command honor guard.
But while this may bring relief to some families after more than 60 years of trauma and uncertainty, the remains of many more thousands of soldiers in North Korea are as yet unaccounted for and, with even the children of Korean War soldiers aged in their 60s, for some time is quickly running out.
War and division
The Japan-colonized Korean Peninsula was divided in two following Tokyo's surrender at the end of World War II, with the Soviet Union occupying the North and the US the South.
Two new ideologically opposite countries were established in 1948: The southern Republic of Korea (ROK) and northern Democratic People's Republic of Korea (DPRK).
Strongman leaders in both sought full reunification of the Peninsula under their rule, and in 1950 tensions spilled over into war.
North Korean forces, with the backing of both China and the Soviet Union, outmatched their South Korean counterparts, and in the early hours of the conflict US officials on the Peninsula warned of North Korea's "complete air superiority" as ROK forces struggled to repulse North Korean tank units.
"The North Korean objective in invading South Korea is outright control over the Korean peninsula," said an intelligence report prepared for US President Harry Truman shortly after tanks rolled over the border. "North Korea presently intends to attain a decisive victory through: the capture of Seoul in the next 7-day period."
It warned that South Korean forces were "militarily inferior" to their Northern counterparts and could not repulse the invasion alone.
US representatives began lobbying the United Nations Security Council, then only five years old, to take action.
On June 27, Truman told the American people he had "ordered United States air and sea forces to give the Korean Government troops cover and support."
The first hot conflict of the still evolving Cold War between the US and the Soviet Union, Truman and his advisers viewed the situation in Korea as part of a wider battle against Communism, even drawing up plans to "wipe out all Soviet air bases in the Far East," and dispatching US naval assets to Taiwan to repulse an expected Chinese invasion, should the war intensify.
Before hostilities ceased in Korea on July 27, 1953, more than 1.2 million soldiers were killed on all sides, as well as an additional 1.6 million civilians, many killed by a brutal US bombing campaign which left most of North Korea in ruins.
The armistice agreement signed on that day established the 250-kilometer (160-mile), heavily fortified demilitarized zone (DMZ) between the two Koreas, formalizing the division of the Peninsula and separating families on either side of the de facto border as each country moved further and further apart even as governments in both still advocated for official unification.
Also cut off from the outside world, left behind inside an increasingly isolated North Korea, were the remains of thousands of US troops never recovered from the battlefield.
According to the US Department of Defense, 7,697 personnel from the Korean conflict are still unaccounted for, 5,300 of whom are believed to be north of the 38th parallel.
Since 1990, the remains of 340 soldiers have been handed over by North Korea via the DMZ.
An additional 200 sets of remains are believed to have been identified by Pyongyang as likely belonging to US troops, which officials in Washington expect to be handed over in the coming days.
While arrangements have yet to be made, a spokeswoman for US Forces Korea said the remains will likely be handed over via the United Nations authority at the DMZ, as in the past.
After a repatriation ceremony, they will be transferred to a state-of-the-art military facility in Hawaii, the largest skeletal identification laboratory in the world, where they will be identified "using forensic anthropology, odontology, DNA and other scientific methods."
First, skeletal remains are examined to ascertain a "biological profile," including sex, race, stature and age at death, as well as information that can be gleaned about the cause of death or medical conditions that could be used to identify the remains.
Most important are DNA evidence and dental impressions that can be taken from the remains, as these are the best chance of linking them to missing military personnel.
For years, the military has encouraged family members of Korean War soldiers to donate DNA that can be potentially used to identify their relatives' remains, taking three cheek swabs per person to build up a collection of cells that can be matched to bones and other material recovered from battlefields or disinterred from unmarked graves.
"The US has a very well established team dealing with such remains for a long time now," said Dr. Philip Beh, a professor at the University of Hong Kong's Department of Pathology. "Once the bones get back to the US there's a lot they can do."
Key to carrying out identification based on remains is how well they have been exhumed and stored.
"If it has been stored in a pretty dry and clean facility, then in terms of getting measurements from the bones, that's very doable," said Beh. "How much in terms of DNA you can collect from the bones really depends on the conditions that they may be in."
He added that if the set of bones is relatively complete, and particularly if dental remains are recovered, identification could potentially be done in a matter of days.
Around 90% of missing Korean War soldiers have some kind of family DNA information on file for them, according to the DOD.
One of those who has donated DNA is Hebert, who joined other members of her family in providing as much data as possible to the military in the hope that it will one day lead to the remains of her father, Karle Seydel.
US military records show that 1st Lt. Karle Seydel was killed on December 7, 1950, during the Battle of the Chosin Reservoir, a successful effort by Chinese troops to push US forces back into South Korea.
"Karle was a terror on that hill," fellow soldier John Hinds wrote later in an account shared by the Hebert family with CNN. "I didn't get to know him too well but my memory of him in that battle is vivid as we assaulted the hill he was fearless and looked like someone out of a John Wayne movie."
At the time of her husband's death, Rosanne Seydel was staying with her parents in coastal Washington state, caring for her two young children. They received the news by telegram, not knowing what information the message would contain until they collected it from a local town.
"They had to pick it up," Hebert said. "It's not like in the movies."
In a later telegram to Rosanne in February 1951, Maj. A. R. Carson of the US Marine Corps Personal Affairs Branch wrote that Karle "lost his life as a result of a missile wound sustained while he was engaged in combat."
"I am sorry to tell you that ... his remains were not recovered," he said. "You are assured that every effort is made to recover the remains of our gallant marines who have fallen in battle."
"You will be promptly notified of any further information received," the message continued, adding that "it is presumed" Rosanne would pass on the information to Karle's mother.
Five years later, in 1956, Seydel's Marine record was updated to note the "non-recoverability of remains."
An end to war
Decades later, Rosanne, now 92, is still hoping her husband's body will be found.
Earlier this year, she and Herbert traveled to South Korea as part of the Revisit Korea Program organized by the ROK's Ministry of Patriots and Veterans Affairs.
They were in the country when President Moon Jae-in met with Kim Jong Un and signed an historic accord pledging to work towards the end of the Korean War.
"To finally go there, to be in Korea that historic week was fantastic, dreamlike, and so rewarding," Hebert said.
During the trip, one man was informed that the remains of his brother had been recovered in South Korea. "He was so thrilled for the rest of the week," Hebert said. "He was just glowing, this search had gone on for so much of his life."
While she did not leave the Peninsula with her father's remains, she returned home with a newspaper bearing a large full page picture of Moon and Kim and the headline "Koreas to declare end to Korean War."
As she watched Trump meeting with Kim in Singapore weeks later, Hebert was remind of the lyrics of a widely covered 1950 song by Ed McCurdy: "Last night I had the strangest dream, I'd ever dreamed before. I dreamed the world had all agreed, to put an end to war."
While hundreds of remains are due to be handed over soon, a formal end to the war and improved relations between North Korea and the US are likely necessary for the recovery of the remains of thousands of other soldiers still in the country.
Many of those corpses, the result of large, bloody battles, will be buried in unmarked and mass graves, which will require careful exhumation and make ascertaining which bones belong to whom far more difficult.
"You would have to send teams in, have to survey the ground, get a sense of what the lie of things are," said Beh, the University of Hong Kong expert. "It would be a long, long exercise."
At present, there are no plans to do so, and having US military investigators inside North Korea would require a massive step forward even for a relationship that has seen major improvements in recent months.
For many family members of the missing, time is running out. During Hebert's trip to South Korea, "there were a number of very senior adults, a lot of gray and white hair."
Reflecting on her own mother's determination and longevity, she said that they're thinking "if there's anything left they can do, they're going to get it done before they pass on."
Copyright 2018 by CNN NewSource. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.