Transcript for Woman's emotional reunion with biological father
My name is Amanda and I've never met my father and I want answers. Reporter: After two devastating false leads, Amanda Holdiness is still determined to find her biological father. It's just -- it's been an emotional roller coaster. Reporter: Now she has new hope. Her mother offers her own DNA so that her blood relatives will be eliminated from the pool of matches. That investigative genealogist, Pam Slaton, will search in the ancestry.com database. Let's see who's sharing this DNA. It's like searching for a pot of gold, in a weird way. Reporter: After sifting out Amanda's maternal biological relatives, she can now focus only on the paternal DNA matches. It leaves her with only two second cousin matches. So I had to figure out the common denominator between those matches and I was able to come up with the name, a last name of hurt. Reporter: A new last name. A huge breakthrough. Pam runs with it compiling a list of a half dozen age-appropriate men in Wyoming with that last name. She sends Amanda the list. I want this chapter to be over with. Reporter: A hopeful Amanda jumps on Facebook to track down photos of the men. There is one photo that she is drawn to in particular. You see the facial features. I mean, you see the lips. Reporter: She messages that man. And halfway across the country in wind-swept eastern Wyoming -- There I was minding my own business and this thing pops up. Reporter: A man named Larry herot is on the receiving end of her questions. I he tells her, yes, he knew her mom in the 1980s. I had one question. Was your mother ever in the army National Guard? She goes, yes. I wanted to cry, I wanted to jump up and down. He actually knows my mother. Reporter: Larry says she dated for a month but he didn't know she had gotten pregnant. Loved her to death. Strong woman. And I appreciated that. The red hair got me. I love redheads. Reporter: However, Amanda's mother Vivian says she doesn't remember Larry at all. He was a truck driver back then. Just as he is today. Working out of a small city called Casper with four adult children of his own. There we go. We're ready to rock and roll, kiddies. Reporter: Now Larry herot becomes the third in a list of potential fathers to agree to a DNA test. It's been probably about two and a half weeks since he sent it in. Reporter: It is an excruciating wait. Amanda is about to get the call giving her the latest test results. I'm so nervous right now. I cannot wait till I get that call. Hey, there. Hey. How are you. So are you ready? Yes, ma'am. What's your gut telling you? My gut's telling me that he's the one. Guess what. What? He is your father. He is? He is. Oh my god. Giving me goosebumps. Thank you so much. You must be so relieved. I just knew it. You know that gut feeling. I just had that gut feeling that he was the one. You never had that before, did you? No. Is he on standby now waiting for the call to come in? Yes. Well, then why don't I give you a kiss. Thank you so much. Thank you, Amanda, love you, honey. Love you too. Bye-bye. Oh, god. God, let me call him. Hello. Daddy? Yes, ma'am. You're my daddy. I am? Yes. Yes? Reporter: They promise to meet soon. Okay, sweetie. Okay, love you. Love you too. Okay, bye-bye. The chapter's closed now. I have a daddy. I can't wait to see him. I can't wait to see him. Now a new chapter for Amanda begins. She and husband Mack have traveled to Wyoming to meet her dad. I know I'll be really happy to see her. And to hold my little girl. I'm tearing up now. Just thinking about it. I just can't wait to show her how much I love her. It's going to be good. Reporter: They are finally about to be face to face. The embrace Amanda has waited for for a lifetime. Finally. Oh, finally. I have another piece of my heart that has been mended. I knew something was missing. And I finally found it. My boy. Twins, really. Pretty much. I look just like you. I'm telling you. Reporter: Over the next several hours, we were with them. Larry literally did not leave Amanda's side. This is Amanda. This is Richard. Reporter: Bringing her to work. Great to meet you. Hi. Reporter: Later at dinner, Amanda would meet her uncle. How are you doing? Doing good. Reporter: Larry momentarily leaves Amanda's side so his brother can chat with his newfound niece. You've got to move, you've got to trade with me now. Reporter: That seating arrangement doesn't last long. You can sit with your daughter. Reporter: After 32 years apart, these two plan on savoring every moment they can now spend together. I'm so happy right now. This is awesome. Reporter: For "Nightline," I'm Elizabeth vargas. Our thanks to Elizabeth vargas.
This transcript has been automatically generated and may not be 100% accurate.