Munguia was last seen departing her residence on McKnight Street in Odessa, Texas at approximately 1:00 a.m. on May 28, 1981. She was planning to drive to a friend's house in Oklahoma City, Oklahoma at the time. Munguia never arrived at her destination and has not been seen again. Her car was found abandoned at Will Rogers World Airport in Oklahoma City on November 14, 1981, nearly six months after Munguia's initial disappearance. Authorities determined that her vehicle was parked in the airport's lot for at least eighty days prior to discovery. There was no trace of Munguia at the scene.

Foul play is suspected in Munguia's disappearance; her family does not believe she would have abandoned her young son or left without telling anyone.