Members of a crowd numbering tens of thousands smoke marijuana simultaneously at 4:20 p.m., at the Denver 420 pro-marijuana rally at Civic Center Park in Denver on April 20, 2013. Even before the passage in November 2012 of Colorado Amendment 64 promised the legalization of marijuana for recreational use, April 20 has for years been a celebration of marijuana counterculture, and the 2013 rally draw larger crowds than previous years. (Associated Press)

Photo by: Brennan Linsley

Members of a crowd numbering tens of thousands smoke marijuana simultaneously at 4:20 p.m., at the Denver 420 pro-marijuana rally at Civic Center Park in Denver on April 20, 2013. Even before the passage in November 2012 of Colorado Amendment 64 promised the legalization of marijuana for recreational use, April 20 has for years been a celebration of marijuana counterculture, and the 2013 rally draw larger crowds than previous years. (Associated Press)