University of Colorado officials say they will close the Boulder campus to visitors Saturday to prevent people from gathering for the annual 4/20 marijuana celebration.This April 20 is the first since Colorado voters legalized marijuana use and limited possession in November.  CU officials have said the annual April 20th smoke-out disrupts academics, even though this year's celebration will fall on a Saturday. Last year, university officials closed the campus to outside visitors on 4/20, and Norlin Quad - which drew up to 12,000 people in the past - was shut down altogether. Campus officials even spread a fishy smelling fertilizer on the grass to deter crowds.The Denver Post has more on this story.

University spokesman Bronson Hilliard tells the Daily Camera a massive 4/20 rally is planned at Denver's Civic Center Park, and he hopes anyone who wants to celebrate marijuana use will head to the larger city.