Officials at the University of Colorado at Boulder are planning locking down the campus to visitors on Friday in response to the annual "4/20" marijuana rally.

Every year thousands of marijuana supporters gather on the campus at the Norlin Quad and participate in the marijuana smoke out, but the size of the crowd has swelled to uncontrollable proportions.

University Chancellor Philip P. DiStefano released a statement detailing the reason why there is such a strong effort this year to deny the student gathering on the school's website.

"The gathering disrupts teaching and research right in the heart of the campus. The size of the crowd has become unmanageable, and limits our faculty, staff and students from getting to class, entering buildings and doing their basic work. It needs to end," according to the statement.

Classes will remain open and students will be allowed on campus but police will be at every entry point checking school identification and denying access to visitors.

The gathering point, Norlin Quad, where past marijuana rally supporters have gathered, will be closed to all people on April 20.

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To make sure that all people remain off the quad, the school will cover the entire area in a fish-based fertilizer hoping the smell will be enough to deter anyone from venturing onto the quad, according to The Denver Post.

In response to the crackdown "Occupy Boulder" is planning a march that will end near the edge of the school's campus.

On the group's Facebook page instructions are listed for potential supporters. The protesters plan to "meet, march, [and] smoke" and will begin at Broadway and Canyon, ending at a park close to campus.

The school's student body has organized an alternate, student-only event which will be headlined by singer Wyclef Jean at the Coors Event Center the same day as the marijuana rally.