Amateur investigators consider whether Lori Vallow Daybell’s missing daughter might be a victim of one of Yellowstone National Park’s thermal pools

Two children vanish and an Idaho mother won’t say where they are. In their first network TV interview, the woman’s mother and sister say she’d never harm her children. So where are the kids? CBS News correspondent Jonathan Vigliotti reports for “48 Hours” in “The Missing Children of Lori Vallow Daybell.” 
Lori Vallow Daybell has gained worldwide notoriety for refusing to tell authorities the location of her two missing children, Tylee Ryan, 17 and Joshua “JJ” Vallow, 7, who have not been seen or heard from for nearly eight months. Police have said that both children are in danger, and that Lori knows their location or what has happened to them. As she sits in a jail cell awaiting trial for child abandonment, armies of amateur, at-home sleuths have dedicated countless hours online to bringing Tylee and JJ home.
Tylee Ryan, 17 and Joshua “JJ” Vallow, 7, at Yellowstone National Park on September 8, 2019 — the last time Tylee was seen. At right is their mother’s brother Alex Cox.  There is no evidence Tylee ever left the park.
“We came together online to be able to give any resources that we had to be able to find the children,” Dee Ann Carter, who belongs to a Facebook group that is over 14,000 strong, told Vigliotti.
The group is called Christmas Misery, a name inspired by the time of year the children were announced missing from the small East Idaho town of Rexburg. Carter says their ranks include local residents, such as herself, and those from as far away as Australia. Annie Southam is also a member and believes that with their diverse career backgrounds — including attorneys, law enforcement and healthcare workers — they are well equipped to hunt for clues online and crowdsource theories for where the children might be and what could have happened to them.
“And with so many people with so many different areas of expertise putting those pieces together hopefully the whole puzzle can kinda be solved,” Southam said.
Group members are constantly sharing updates on the case and are working together to decipher evidence as it becomes public. Southam has been working on a timeline that tracks the key people involved, including Lori and her husband, Chad Daybell, a doomsday author and podcaster. The two tied the knot at a ceremony in Hawaii a little over a month after Lori’s children disappeared.
“I just have been keeping track of the events that have happened”, Southam said, “They were definitely in Rexburg on this date. They were definitely in Hawaii on this day.”
One date that has received particular scrutiny is September 8, 2019. It’s the day Tylee was last seen in Yellowstone National Park, evidenced by pictures authorities have released of her, JJ, Lori and Lori’s brother Alex Cox in the park. There is no evidence Tylee ever left.
“I think if all they have to go on is that one picture, I think it’s going to be like trying to find a needle in the haystack,” said Aaron Teasdale, a Yellowstone expert and CBS News consultant.
Teasdale says that with over 2 million acres of untamed wilderness, Yellowstone tends to hold on to its secrets, and as authorities reportedly prepare to search the park, he is afraid there might not be much to find.
“There is a chance that the evidence could be lost forever in a case like this… There are rivers that sweep things away… there’s deep forest,” says Teasdale. “There are a lot of remote places where if you didn’t know where someone had gone, it would be quite difficult to even know where to look.”
Idaho mom Lori Vallow’s mother and sister speak out on “48 Hours”
Christmas Misery has raised one theory of how evidence could have been destroyed. 
It involves Yellowstone’s many thermal pools, known colloquially as “hot pots.”
“Online there’s a lot of speculation that possibly Lori and Alex killed Tylee in Yellowstone and disposed of her body in one of those hot pots,” Southam said, “Because there are cases of people that have fallen into those and their bodies just completely dissolved.”
“These pools are not only boiling, many of them have the acidity of battery acid,” Teasdale said. “So not only will you die quickly because of the heat, but your body will dissolve in short order.”
Teasdale, however, is skeptical of this theory, because the pools near where Tylee was pictured are in a very heavily traveled part of Yellowstone. In order to remain undetected, it would have required a trip miles into the backwoods and intimate knowledge of the park. He also says that there are several variety of pools with different acidities and composition, so if someone were to try to dispose of evidence this way, they would need to choose the correct one.
“So if you don’t pick the right pool, it’s not necessarily gonna work,” Teasdale said. “So do I think it’s likely that in this case, this is what happened? I think it’s highly unlikely.”
With so much time elapsing since Tylee and JJ’s disappearance, and no sign that Lori will be providing answers anytime soon, Carter and the rest of the group work with fading hope to find the children themselves.
“The more that she sits there without answering anything is more days that these kids are missing and you start to think the worst, which you don’t want to,” Carter said. 
The FBI is asking anyone who was in Yellowstone National Park on September 8, 2019 to upload photos or video to its website.