Lorie Ann Hill, 49, was arrested last week on suspicion of public intoxication. Police said an administrator walked in to a classroom to find Hill intoxicated and partially dressed, though no students were present.
"She was found in an empty classroom by an assistant principal," Bob Haley, police chief at the Wagoner Police Department, told ABC News. "He found her with no pants on. He had never seen her before."
The police officer on scene could "smell a strong odor of an alcoholic beverage coming from her breath," according to the police report on the incident.
The officer then performed field sobriety tests on Hill, and she failed all the tests, the police report said.
"When our officers interviewed her, she did admit to having some vodka before coming to school," Haley said.
When the officer asked her if she had any more vodka left, Hill reportedly said there was more in her car, which was parked in the school parking lot.
Haley said she was only booked on the public intoxication charge because there wasn't a witness to prove that Hill actually drove to school under the influence of alcohol - even though that's what authorities believe happened.
A judge set bail at $149, which Hill quickly posted after pleading not guilty at her arraignment.
School officials did not immediately comment on the situation.