Search for missing Idaho girl eyes Yellowstone National Park

Sources tell CBS News investigators are considering searching inside Yellowstone National Park as they look for two missing Idaho children. Tylee Ryan and Joshua “JJ” Vallow were last seen in September. Their mother Lori Vallow was arrested in Hawaii and faces child abandonment and desertion charges. She's fighting extradition to Idaho.

As Lori Vallow sits in a Kauai jail cell, sources close to the investigation tell CBS News detectives are waiting for the snow to melt in Yellowstone National Park as they continue the search for Vallow's 17-year-old daughter Tylee Ryan. Park officials declined to comment citing an active investigation.

According to court documents, Rexburg Police said phone records show Ryan visited Yellowstone with her mother, brother “JJ” and uncle ‪on Sept. 8. Police also "…obtained a photo from Lori Vallow's iCloud account…" of Tylee in the park. They say there's been no sign of life since.

Doorbell camera footage has also surfaced showing what it is believed to be JJ Vallow playing with a neighbor in September just days before he disappeared.

“This is a very atypical defendant and a very unusual case,” David Leroy said.

Former Idaho Attorney General David Leroy says Idaho has never seen a case like this.

“The implication of a parent who will not cooperate and disclose their location...is something very untoward has happened to these children,” Leroy said.

As authorities continue to search for any clue, the ex-husband of Vallow's niece claims in divorce filings his ex-wife knows where the children are and was involved in a cult where numerous members, adults and children alike, were killed off like flies.