Christian Munn-Holliday, a 22-year-old Katy mother, has not been seen since she left the scene of a crash on Interstate 10 in Louisiana on Sept. 30.

One week later, her family is in Louisiana searching for her. Her father, Robert Munn, is offering a $20,000 reward for information that brings her home.

Louisiana State Police said the two-vehicle crash happened during the early morning hours of Sept. 30 on I-10 eastbound near milepost 128 in Iberville Parish, on the Atchafalaya Basin Bridge near the Whiskey Bay exit. Trooper Shelby Mayfield said investigators believe Munn-Holliday was driving one of the vehicles and left the scene on foot after the collision, WAFB first reported.

When Iberville Parish Sheriff's Office deputies arrived, they found one occupied vehicle and a second vehicle that was empty, according to WWL-TV. Munn-Holliday's cell phone last pinged at the crash scene. Investigators believe she was traveling to Baton Rouge, WWL-TV reported.

Her family told the Houston Chronicle she dropped off her children with her parents the evening of Sept. 29 and left for Louisiana in a gray BMW.

On Oct. 1, Louisiana State Police learned Munn-Holliday had also been reported missing to the Harris County Sheriff's Office. HCSO is the lead agency for the missing person investigation. Louisiana State Police leads the crash investigation.

Her mother, Lareshia Dunn, told KHOU she suspects foul play. Authorities have not confirmed that but continue to investigate.

"No, I'm not leaving Louisiana. Till I find my baby," Dunn said.

The family reached out to the United Cajun Navy, a nonprofit search and rescue organization, which is supporting Louisiana State Police in the search. Josh Gill, an incident commander with the group, said the effort has included boats, drones, ground teams and canine units. The Iberville Parish Sheriff's Office and Team Texas K9s are also assisting, according to a United Cajun Navy update on Facebook.

The search area spans the miles-long bridge and surrounding swampland. The United Cajun Navy said possible severe weather could complicate the effort.

The family has also launched a GoFundMe to raise money for a private investigator, with a goal of $3,000. As of Thursday, Oct. 8, the campaign had raised $2,006 from 51 donations.

Munn-Holliday is described as 5 feet 6 inches tall, approximately 105 to 120 pounds, with brown eyes and black hair. She was last seen wearing a purple one-piece bodysuit with a blue jean jacket, according to the Houston Chronicle. She has several tattoos, including roses on her shoulder and chest, Arabic letters on her arm and neck, and names including "Lareshia," "Major'Lee" and "Robert."

Anyone with information about Munn-Holliday's whereabouts can call the Harris County Sheriff's Office at (713) 221-6000.