Dramatic rescue of injured hiker who got trapped under a boulder for 12 HOURS after he slipped in the California mountains - and managed to call for help after cutting his pants open with a pen knife to grab his phone

An injured hiker who slipped and got trapped under a massive falling boulder in California for 12 excruciating hours has been miraculously rescued after he cut his pants open with a pen knife to get his phone and he dug his way out from under the rock.

Jason Koch, 48, was hiking in the heavily wooded mountains of Mount St. Helena near Calistoga, California searching for his missing drone on Monday November 23 when he slipped on a rock at 5pm. 

When he fell a large boulder fell on top of him and pinned his backpack and right arm to the ground for hours, all while his phone was tucked into his pocket. 

'Something slams into me and I have moments of excruciating pain,' Koch said from his hospital bed to CBS News. 

'I found that my left arm was stuck down under below me. I’m kind of laying with my chest sort of flat, but my hips kind of rotated sort of sideways. So it’s a really weird position to be laying in,' he added.

For hours Koch tried to free himself and reach his phone in the freezing cold. 

He said he had a flashback to the movie 127 Hours, where James Franco plays a rock climber who got trapped and had to cut off his own arm to free himself and get help. The movie is based on the life of American outdoorsman Aron Lee Ralston.

'I actually reached across with my pen knife, cut my pants open and was able to reach into the pocket and pull my phone out,' Koch said to Live5News.  

Hiker Jason Koch, 48, was rescued early Tuesday after he slipped and got trapped under a massive falling boulder for 12 excruciating hours. A view of him being warmed with foil blankets after he was found by rescue crews above

A view of the boulder that fell and pinned Koch to the ground late Monday during his hike in Mount St. Helena above 

'I actually reached across with my pen knife, cut my pants open and was able to reach into the pocket and pull my phone out,' Koch said on his rescue

After cutting his phone free and digging his way out from beneath the rock he called for help and was located by California Highway Patrol rescue crews. Due to the rough terrain and his injuries they waited for daylight to airlift him to safety early Tuesday 

But before he could dial 911, he had to escape from under the rock. 

Koch freed himself from the boulder by forcing his helmet off, which was keeping him stuck under the tight space. 

'I made a whole bunch of efforts. And finally I was like, you know what? You’re not trying hard enough. Try harder. So I’m like, I forced my hand up even harder and was able to get that pinch and popped free. And I was so elated. I was like, in your face. Right,' Koch recalled.

Once the helmet was off he noticed the rock pinning him down wiggle a little and he realized he could move it. 

Koch then started to move with his face on the ground and grabbed a nearby branch and started digging into the dirt underneath and around the rock. He made a hole and then shoved the rock into the ditch to free himself. 

'Then I was able to bring my arms up and I was able to back backwards out of my backpack and at that point I was able to get out from underneath the rock,' he said.

Finally free, he called 911 in the pitch black darkness with just six percent battery left on his phone, as per the Napa Valley Register.

Koch said he had a flashback to the movie 127 Hours, where James Franco plays a rock climber who got trapped and had to cut off his own arm to free himself and get help. A view of Franco trapped amid rocks in the movie above

Koch said remembering the movie 127 Hours reminded him to stay positive and to cut his pants to reach his phone

The California Highway Patrol helicopter crew said it received a 911 call at 2.20am near the Oat Hill Trail in the area known as the Palisades. The CHP H-30 crew flew to the GPS coordinates, which were provided by Cal Fire, and located him using night vision goggles and their FLIR system which is a thermal camera that detects infrared energy, or heat, and converts it into a visual image making it easy to track

A view of the rescue helicopter that found Koch above 

The California Highway Patrol helicopter crew said it received a 911 call at 2.20am near the Oat Hill Trail in the area known as the Palisades.  

The CHP H-30 crew flew to the GPS coordinates, which were provided by Cal Fire, and located him using night vision goggles and their FLIR system which is a thermal camera that detects infrared energy, or heat, and converts it into a visual image making it easy to track. 

After locating him by air, Koch signaled the helicopter using a small flashlight. 

The crew then hiked for one hour off the trail and reached Koch.  

He was found with 11 broken ribs and a torn aorta, which is the main artery that carries blood away from the heart to the rest of your body. 

An aerial view of airlifting Koch to safety above. He was found with 11 broken ribs and a torn aorta, which is the main artery that carries blood away from the heart to the rest of your body

However, the rescue crew realized they could not get him out due to the tough terrain and his injuries. 

Thankfully his injuries were not life-threatening and the crew decided that a first light rescue was the best way to save the hiker. 

The crew then waited for daylight and built a small fire with their survival gear and warmed up the hiker up using foil blankets in the frigid low 30s temperatures. 

When the sun rose the crew airlifted Koch out of the area and transported him to an ambulance that was waiting for him at the Calistoga Fairgrounds and he was transported to a local hospital.

'I'm grateful for my family, my friends and my life,' he said. 

A GoFundMe has been created to help with his hospital expenses and has reached over $1,000 so far.