reporter: tammi saw how committed toni was to her patients. sometimes it was hard to get her to leave the office. so tammi was charmed when one day in september harold asked her for help. you get a phone call out of the blue from harold. yes, about two weeks before their anniversary he phoned and said, hey, tammi, i want to surprise toni for our anniversary. can you help me out? reporter: it was their 12th wedding anniversary. harold wanted to celebrate with a surprise trip to one of colorado s wonders, rocky mountain national park. so you re being really sneaky in all of this. i am. i mean we d all love for our husbands to call and do something fun like that. so i made her schedule so that she could be done and out of the office by 3:00, but it looked like she would be there till 5:00. reporter: the big day was september 28, 2012. he came into the office, and the other girls thought it would be fun to really surprise her. so they put him in an exam room.
things are not right. reporter: tammi says that even though toni seemed to adore her daughter haley, she often gave up mommy time, staying late at the office instead. we would be done. patients gone, staff gone. and she would still be on her computer. but it wasn t work-related. it was playing games. and so we thought, that s so odd. why does she stick around the office? we started to think that maybe she just didn t want to go home and maybe because of harold. reporter: if there was trouble in the marriage toni never said so directly. not to friends, not even to family. todd and rhonda worried maybe she was afraid to say too much. i think he had held control over toni with haley, you know? his parents heard conversation that they weren t meant to hear that he held, you know, divorce over her head. i ll divorce you. yeah. and you won t see haley and, you know, that kind of thing.
reporter: a colleague shot this cell phone video. so she picks up a chart, walks into the room like she normally would, and then there s her husband. and she s like, what s going on? and he says, you know, we re going away for the weekend, happy anniversary. and she s like, no, no, no, no. i can t do that. and he says, you can. tammi fixed the schedule so you re ready to leave. reporter: this was well orchestrated. yes. reporter: this anniversary plan. yes. reporter: harold thought of everything. he hired baby-sitters for haley. he d even packed toni s clothes. she couldn t say no. i mean, she just, you know, he had it all worked out, so off they went. reporter: harold henthorn, the consummate planner, had pulled it off. now the perfect anniversary weekend could begin. the couple left denver on a friday afternoon and headed north. harold booked a room at the stanley, a historic beautiful hotel in estes park.
was he very supportive? i asked her how this was going, that this had to be incredibly stressful. and she said, her exact comments i ll never forget these words. life with harold is hard. reporter: brother todd and sister-in-law rhonda also looked back and thought how difficult it could be to get toni on the phone without harold listening in. you call their home number, you call her cell phone number, and you could call his cell phone number. reporter: and he would answer? he would answer. when we spoke to her it was never just her. it was always him and her in the background. reporter: tammi recalled how harold used to come into toni s office as if he owned the place and how in his presence, toni, the self-confident doctor, seemed to melt away somehow. she said i ve just learned long ago it s just better to let harold be right. reporter: did that make you kind of sad? that made me very sad, and that s when i really thought
i got a call from christy at our office and all she said is, tammi, toni fell. reporter: what did you think when she said she fell? i just said, is she okay? no, she died. and i fell to my knees. and my husband said, oh, my gosh, what s going on? and i said, dr. henthorn fell off a cliff. reporter: everyone was heartbroken for toni. harold. and, most of all, the henthorns 7-year-old daughter haley. i put myself on the mountain and at the moment that she probably knew, well, this is it, you know. i know her thoughts were of haley. reporter: about 150 people die in national parks each year. in rocky mountain national park, the leading cause of death is falling. before i wrote this book, i didn t know that the national park had investigators. reporter: journalist michael fleeman covered the death of toni henthorn. i just thought the extent of