FARGO, N.D. (AP) — An American Indian woman whose body was found in a submerged truck in a North Dakota lake was strapped into the passenger side with a seatbelt around her waist, according to court documents released Wednesday.

Olivia Lone Bear, 32, was reported missing to the Three Affiliated Tribes Police Department on Oct. 27, 2017. A sonar-equipped boat found the truck July 31, 2018, with Lone Bear’s body inside. No obvious injuries were found on her body, and an autopsy failed to determine the cause of death.

Three search warrants were unsealed Wednesday after U.S. Attorney Drew Wrigley of North Dakota and other federal officials traveled to New Town to update Olivia Lone Bear’s family members on the investigation into her death.

The FBI also announced a reward of up to $10,000 for information on her disappearance.

In addition to revealing that Lone Bear was strapped in on the passenger side, one affidavit said a witness told investigators that one of the last text messages he received from her said she had been to a bonfire and was going “mudding” — a practice of off-road driving usually conducted near rivers or swamps. The next message from Lone Bear read “Good Bye!”

None of the people interviewed by investigators identified anyone who went to a bonfire or went “mudding” with Lone Bear, according to the affidavit.

Earlier this summer, family and tribal members complained about the lack of information in the case. Matt Lone Bear, her brother, told the Bismarck Tribune that the meeting was “very professional and sincere.”

“Considering we went from not knowing anything to this, I think it’s definitely a big step in the right direction,” he said.

“Olivia’s family and members of her community want to know what happened to her and so do we,” Minneapolis FBI Special Agent in Charge Jill Sanborn said in a statement.