She was at home and had just been listening to a visitor remark on the serenity of the surrounding landscape, when they were interrupted by a mighty roar.
"I went to the window and across the valley I could see a wall of mud 20ft (6m) high and travelling at what seemed like 100mph (160km/h). The next thing I knew we were hit. We were hit and we were moving."
The blast ripped her home from its foundations and sent it careering down the hillside. By the time it came to rest - a quarter of a mile away - the torrent of mud and rock was threatening to engulf her.
But 63-year-old Ms Youngblood - whose ancestors helped establish the town of Oso - somehow managed to claw her way out from beneath a huge pile of furniture and raise the alarm.
Scanning the horizon from a rescue helicopter a short while later, she realised that the entire town had been swept away.
Ms Youngblood is not the only resident of this scenic lakeside town to have witnessed the kind of scenes that are normally confined to nightmares.
At a Red Cross shelter in the nearby town of Darrington I met James Michael.
The 13-year-old was playing outside at his friend Elijah's house when they heard what sounded like several bulldozers bearing down upon them.
James looked round to see homes being torn in two and people being sucked into a giant sea of mud.
"I thought: This is it, I'm going to die," he told me. "And then it just stopped."
It stopped and everything fell silent. And that was when a four-year-old boy clambered onto a rooftop.
Jacob Spillers was upstairs at his home when it was hit by the deadly tide of mud and rock. His father and three siblings were watching TV downstairs.
A helicopter rescue team spotted Jacob up to his knees in mud, and winched him to safety. And that is where he met Robin Youngblood.
"He was shaking like a leaf so I wrapped him in a blanket and put him on my lap," Ms Youngblood said. "He kept asking for his mummy and I told him: "We're going find her."
Jacob was eventually reunited with his mother, but there has been no sign of the rest of his family since the mudslide wiped their town off the map.
The same goes for some 90 other members of this tight-knit community. Nothing's been seen or heard of them since Saturday.
I met Ms Youngblood at her new home - a hotel room in the nearby town of Marysville - just as reports had started to emerge that suggested the mountains around Oso were an accident waiting to happen.
It seems a government scientist warned of the dangers of a major mudslide in the area some 15 years ago, only for home building and other commercial activities to continue apace.
Understandably perhaps, Ms Youngblood was angry, not only because she wasn't informed of the dangers when she moved back to Oso two years ago, but also because big business had also allowed quarrying to take place in the mountains.
This, she says, meant there was nothing to hold the earth in place once it became saturated with water.
As if losing family, friends and everything they own wasn't bad enough, throw in the suggestion that maybe it could have been avoided and you have some idea of what the people of Oso are grappling with right now.
And there are the nightmares - which Ms Youngblood believes could last a lifetime.
"Every time I close my eyes I see the wall of mud, and I hear that sound," she told me. "I don't think I'll ever be able to forget it."
Robin Youngblood will never forget the moment the mudslide hit.