The Princeton Review, a college-admissions company, found the schools where marijuana use is most common.

In a survey of 140,000 students, most colleges that made the list were located in states where cannabis is legal, like Vermont, California, and Colorado.

The No. 1 school for weed smokers is the University of Vermont, in Burlington.

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For many, toking up has been as integral a part of the college experience as ultimate Frisbee and late-night study sessions. And while the activity has often been shrouded in secrecy, the mainstreaming of marijuana now has college students openly discussing their smoking habits.

Enter the Princeton Review's 2020 edition of "The Best 385 Colleges," which includes among its 62 rankings a list on campus cannabis use cheekily labeled "Reefer Madness."

To find out which colleges are out-smoking the rest, the Princeton Review surveyed 140,000 students in 385 schools, asking them, "How widely is marijuana used at your school?" Not surprisingly, many of the colleges with students reporting highest marijuana use are in states where recreational use of the drug is legal.

According to a 2017 Monitoring the Future study from the University of Michigan, 38% of college students aged 19 to 22 have reported smoking weed in the past year.

And as a sign of the times, weed isn't just being smoked on campus anymore — it's being taught. Some schools, like Cornell University in New York and Colorado's University of Denver, are offering cannabis courses. The University of Maryland School of Pharmacy will even offer a master's degree in medical cannabis, according to the Wall Street Journal.

Here are the colleges where students report the most recreational use of weed.