Some workers found the woman alive in a cardboard box at the Irving city dump around 9 a.m. Saturday.
Police said she was barely clothed and didn't have any idea of how she ended up there.
Police said she remembered going out with friends the night before. She went to Angels Bar off of Walnut Hill Lane and Brockbank Drive in Dallas -- a Latin music club that's packed Thursday through Sunday nights.
However, she never went inside because she was turned away at the door for being too drunk.
Around 3 a.m., a man she knew offered to drive her home -- a witness who was interviewed by Irving police told FOX 4 that he saw them in the parking lot.
"I seen a lady and a man arguing," said witness Garvin Smith. "They was just arguing, which is normal out here, but I seen a lady and a man [by a pole], and then the man holds like the lady and walks her this way."
Police say she was so drunk, she fell in the parking lot, but they say she didn't leave the bar by force or deception.
After friends didn't hear from her, they reported her missing to Dallas police just before 7:30 a.m. Saturday.
When she was found at the landfill, she was taken to Parkland Hospital, where a rape kit was done.
While Irving detectives are still waiting for test results, they say she didn't have any physical injuries aside from some scrapes.
Officers looked at footage from multiple video surveillance cameras outside of the club, which police say showed she didn't have any medical or mental disabilities, so there are no signs of a crime right now.
Irving police say detectives aren't willing to share any additional information for now, including details on the man the woman left the club with.
Detectives are still waiting on forensic evidence and interviews over the next few days, which should reveal more on what happened that morning.