The following is a press release sent out by the Public Affairs Office at Yellowstone National Park.

The FBI and the Rexburg Police Department are asking that visitors to Yellowstone National Park on September 8, 2019, submit any photos and video that may assist in the investigation into the disappearance of 17-year old Tylee Ryan and 7-year old J.J. Vallow.

An ongoing investigation has determined that the children were in Yellowstone National Park on that date with their mother, Lori Vallow, and uncle, Alex Cox.  The group was traveling in a silver, 2017 Ford F-150 pickup, with Arizona license plate CPQUINT.  Attached are photos of the missing children, Lori Vallow, and Alex Cox, that were taken in the park on September 8, 2019, as well as pictures of the vehicle.
Law enforcement is seeking photos and video which may have captured images of these persons and the vehicle, or images of crowds and other park visitors where these individuals may be present.  The FBI has established a website for the public to upload photos and video:  FBI.gov/Rexburg.
The public is asked to continue reporting tips in this case to the Rexburg Police Department at (208) 359-3000 or the National Center for Missing and Exploited Children at 1-800-8435678 (1-800-THE-LOST).
According to East Idaho News, Lori Vallow was recently arrested in Kaui, Hawaii in connection with the disappearance of her children. She has been extradited to Idaho, and will appear in court on Friday, March 6.
The case was featured on an episode of Dateline NBC that originally aired on February 14, 2020. To watch the episode, click here.