(CNN) – Two brave hikers came across a lime green bottle from a river and immediately alerted authorities about an SOS message that was found inside. Curtis Whitson now has the two hikers to thank for his family being alive today.

Whitson, his 13-year-old son, and girlfriend, Krystal Ramirez, had decided to spend Father’s Day weekend backpacking the Arroyo Seco River in California.

The group spent their days boulder-hopping and floating the river on innertubes, and their nights sleeping under the stars, bundled in lightweight mummy bags, with mesh bags over their heads to keep bugs at bay.

Throughout the trip, the goal for the family was to reach the Arroyo Seco narrows, float through the water shoot and down the waterfall before joining friends to float the last couple of miles down to a campground. After two and half days of lugging 50-pound packs, the family reached the narrows, a spot in the river surrounded by solid rock up to 40 feet high on each side.

However, the water currents were too strong for them to safely pass through.

“My heart sank when I realized the volume of water was just too dangerous to make rappelling down possible,” Whitson said. Typically, he said, there is a rope going through climbing carabiners that have been bolted into the rocks.

“This time, the rope was gone,” Whitson told CNN.

After trying to hike up and over, Whitson and his son kept hitting dead ends.

There was no way out.

The group could not see anything past a bend in the canyon walls, but they heard voices on the other side. They tried yelling for help. They tried carving a message into a stick and throwing it over. But they soon realized a stick would not be enough, so they came up with a new way to get the attention of someone.

Using a lime green Nalgene water bottle, Whitson carved ‘HELP’ into the durable plastic exterior. Ramirez, his girlfriend, had brought scratch paper with her to keep score when they played games. She scratched out a quick note and popped the piece of paper inside the bottle.

The family carved ‘HELP’ on a green bottle

“With one lucky toss, it went right over the waterfall,” Whitson said.

Before settling down, the family spread out their blue tarp in a clearing and assembled white rocks to spell out “SOS.” As the sun set, they used a headlamp to keep that message illuminated.

Some time after midnight the group awoke to the sound of a California Highway Patrol helicopter overhead.

“This is Search and Rescue. You have been found,” someone said over the loudspeaker.

The three made sure to include a note in the bottle

“It was one of the best feelings,” Whitson gushed, “nothing was sweeter than those words uttered by CHP.

“Whitson said he was told two men found the bottle with the family’s note, floated down to the trailhead, then hiked a couple of miles and reached the campground where they alerted the camp host.

That host told Whitson about the hikers, but added the two left before the rescue without giving their names.

The family was told to stay put and stay warm, and a rescue crew arrived early the next morning. Whitson still gets emotional recalling the rescue and his gratitude for both the crew members and his family.

Now, he wants to find the two hikers who found his family’s message and saved them.