Schulze was last seen leaving her dormitory on the Middlebury College campus in Middlebury, Vermont on December 10, 1971, the first day of final exams before Christmas break started. She was on her way to take a final exam with her friends when she said she had forgotten her favorite pen and was going to go back to get it. Schulze never arrived at the exam and has never been heard from again. She left her identification, checkbook and all her personal belongings behind when she vanished. She may have been carrying $30 in cash with her. Campus security was alerted to Schulze's disappearance two days after she was last seen, but her parents were not notified for a week.

Schulze had mentioned the idea of faking her own death and starting life anew prior to her disappearance, but her friends did not take her seriously. In her letters to family and friends back home she admitted she felt homesick and was considering withdrawing from school in the future, but she never indicated she was planning on dropping out of sight or leaving college before the term was over, and she did register for the next semester's classes prior to her disappearance.

There were several possible sightings of Schulze after her disappearance, but none of them were confirmed. Several people made confessions of involvement in her case, but all of their statements turned out to be false. Little evidence is available as to her fate, but Schulze's disappearance is considered suspicious. She was a freshman at Middlebury in 1971, and lived in Simsbury, Connecticut when she was not at college. Her case is unsolved.

Some agencies give the date of Schulze's disappearance as December 11, 1971.