"If you possess marijuana and are over 21, you still may face discipline under the student code of conduct," University of Colorado police spokesman Ryan Huff said.
Gary Gasseling, deputy chief of the Eastern Washington University police department, said that while they await guidance from the state Liquor Control Board, which is creating rules to govern pot, one thing is clear.
"The drug-free environment is going to remain in place," he said.
Even if conduct codes did not exist, marijuana remains illegal under federal law, another key reason that campuses will remain cannabis-free.
The Drug Free Schools and Communities Act requires that any university receiving federal funds adopt a program to prevent use of illicit drugs by students and employees, much in the same way other federal funding for law enforcement and transportation comes with clauses stipulating that recipients maintain drug-free workplaces.
Washington State, for instance, receives millions in federal research funds each year, which prohibits them from allowing substances illegal under federal law on campus.
College dormitory contracts also tend to prohibit possession of drugs, officials said. Dorms and other campus buildings also tend to be smoke-free zones, which would block the smoking of marijuana, officials said.
At Eastern Washington, there is a student-led movement to ban smoking even outside across the entire campus, Gasseling said.
In addition, NCAA rules prohibit student-athletes from consuming marijuana or other illegal drugs.
With all these complications, it is reasonable to expect that some students will be confused by the new laws.
"Some type of communication is going to come out from the university to clarify this," said Angie Weiss, student lobbyist for the Associated Students of the University of Washington.