Transcript for How Texas woman survived 5 days stranded in Ariz. desert

It was a road trip gone horribly wrong. A young woman lost in the Arizona desert for five days filming her struggle to survive on her cell phone right up until the moment she thought she would never see her loved ones again. Tonight her account through dramatic footage and what she did right that saved her life. Here's ABC's Matt Gutman. I love my family. Mom, dad, kalie. Reporter: Recording a good-bye video to loved ones. Something no one expects they'll ever have to do. I just want to go home. I don't even want to do this trip anymore, I'm so scared. Reporter: Especially not 24-year-old amber van heck who just days before began a road trip that should have been the time of her life. But a series of mishaps instead brought her to the brink of death. Three weeks ago the outdoorsy Texas college student set out on a 3,000-mile road trip to the grand canyon all alone. Pretty courageous of you. I don't know if I'd call it courageous. It's more of a -- stubborn, probably. Reporter: She had a couple of particular spots in mind. The havasu falls trailhead, a remote spot in the grand canyon, it has aqua blue plunge pools so popular it requires a reservation. That's the trailhead? Yep. It's in the middle of nothing. Yes. Let's go. Reporter: This week we returned with amber to this fateful spot. The place where, directed by her smartphone, amber turned off highway 64 and onto this dirt road. I trusted Google maps which I shouldn't have. So we're barely a mile off the road. We're driving in empty space. Check that out. Nothing. Reporter: As night falls on March 12th, amber says she drives another hour and a half deeper into the middle of nowhere. When I came to the fence and I was like, oh. There wasn't a road here. That's when I was like, this is not good. That's when I tried going into the gps app and telling it to take me back. It was like, sorry, you have no internet service. Reporter: For a brief moment she's able to get cell service and immediately calls 911. I was in such a panicked state. When they said, what is the nature of your emergency? I let out a sob and I said, please help me. And I heard it drop. And I just -- Reporter: With no cell service for her Google navigation app, amber is about to lose a second precious resource. I was trying to watch my gas. Is that Orange light blinking? It had been blinking. Reporter: Earlier that day she had stopped to gas up her Ford edge and pumps only about one-third of a tank, hoping to save some money. How often do you think, if I just put $5, or just half a tank instead? Every day. I could have spared myself a lot of grief. Reporter: 119 hours of grief to be exact, which amber would battle the triumvirate of no fuel, no cell service, no navigation. In the darkness, she parks alongside the first manmade structure she sees, hoping a sign of life will appear in the morning. She begins documenting her ordeal. Hopefully it doesn't take too long to be found. Reporter: She's actually stranded on one of the largest cattle ranches in Arizona, run by Gary Wilson. It has happened to several other people trying to get across this ranch. Google Earth tells you that you can. But this ranch is actually closed. Reporter: Google did not respond to our requests for comment. A gps industry source previously told ABC news it is important for drivers to keep in mind the gps devices are to be used as navigational AIDS only. It is the responsibility of drivers to exercise common sense." A cowboy usually patrols the area where amber is parked, but again, amber was out of luck. He was gone for about five days. And that just happened to be the time that she was out here. Reporter: Back home, amber's dad, Steven, tries calling her phone and pinging her on her gps app. There is no response. I snapped at my boss that day. Because I was worried about her. Reporter: But there are some encouraging signs. The occasional plane or helicopter overhead. The helicopter just flew by. I got out of my car and waved as frantically as I could. I guess up there it's hard to notice small things on the ground. Reporter: Amber does have some advantages in the wild. The former girl scout and injuring rotc is now putting to use all the survivor skills she's learned. Using large rocks, she spells out the word "Help" to be hen by aircraft above. She also makes a fire. I can't get anything here to burn black, it all burns gray or not at all. Reporter: And luckily for her, she's brought plenty of food and water that she begins rationing meticulously. Three bottles a day should last me for at least a week and a half. Reporter: It's now Wednesday, March 15th. Amber plans to stay put until help arrives. I'm out here for -- 63 hours now. Reporter: Back in Texas, dad begins an active hunt for his daughter. I'd posted in the private Facebook. I said, look, my daughter's missing. I need some people to try to find her. This is the last place I saw her. Reporter: The problem, Stephen references amber's last known location. In New Mexico, where her app pinged him back on Saturday. The next day, suddenly amber sees a vehicle approaching and she sprints into action. Barefoot. I immediately jumped out of my car, tried to run after them, not thinking about my feet, not thinking about anything else. If this is where I get out, it doesn't matter. They didn't see me in their rear view. I'm okay. Reporter: As day four in the hot desert sun comes to a close, amber hits a low point. Almost exactly 100 hours out here now. All I can keep thinking is how much I want my daddy. And my mom. I don't want to be alone anymore. At what point did you decide that you had to rescue yourself? By about the fourth day. I figured there should have been at least a search out. But I hadn't seen anything, heard anything. Reporter: The next morning, amber takes a gigantic risk embarking on what she says would be an 11-mile desperate hike for a cell signal. It's amazing, you can see flagstaff mountains so clearly from here. That's exactly why I chose to walk that way, because flagstaff has cell towers on it. Reporter: After dialing 911 over 70 times, at last a connection. I started crying. Payi saying, please help me. Reporter: She tells the operator she's somewhere between havasu park and the highway that goes to the southern rim visitors center. She's like, in the grand canyon? No, ma'am, I'm in the desert, I've been here five days. I don't know what she was going to say because it was gone. Reporter: Just like that the call dropped. I was heartbroken in that moment. Reporter: She doesn't know it -- We had a virtually unreadable 911 call, up known location, a woman who's panicking -- Reporter: She provided just uh-uh to point Arizona's department of public safety in the right direction. Pilot Joe than nivez and paramedic Edgar vicenet retrace the route. They spot a glare, the top of amber's vehicle. Then amber's sign for the sky. I look down, we see -- must have been 20, 30-foot letters, "Help" written in rocks on the ground next to the car. This has exot got to be it. Reporter: Amber's not there but the rescue team doesn't give up hope because amber wisely had left this message. It said, "I'm not here, I walked east along the road to find cell phone signal, if you're reading this sign, please help me." Let's go. We loaded up. And continued down the road from there. Then I heard a chopper again. And that's when I saw the speck getting bigger. I look, I see someone jumping up and down in the road waving at us. I was like -- they're coming for me. Reporter: After five arduous days, amber van Hecke is stranded no more. Next thing you know I'm two feet from her. First thing that comes out of my mouth was, did you call? All I could answer was high, then ugly sobbing and holding on to him. Reporter: The crew flies her straight to the hospital in flagstaff. I had said, you know what, you do everything right besides running out of gas. If I had to get lost, I wouldn't mind getting stranded with you, you know what you're doing. Reporter: After getting treated for exposure and dehydration, an emotional phone call to her dad. I said, I was worried sick. She said, I thought you were hunting for me. I said, I was -- in the wrong place. Reporter: Two weeks since her rescue, while still healing physically and emotionally, amber says she has no regrets. I did do right things even if I did make mistakes. If I can just share those things that I did right with everyone, if that saves even one life, it's worth it. Reporter: For "Nightline," I'm Matt Gutman in flagstaff, Arizona.

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