CelebStoner has some coverage of a 4-20 party in Boulder, Colorado that puffed its way up to 10,000 people. They have a picture and some video of the event, here's a little snippet:

Stoners celebrated the 4/20 holiday yesterday with smoke-outs all over the U.S. and Canada. But no event was bigger than Boulder's, which boasted a crowd of 10,000 at Colorado University.

Meanwhile, in Santa Cruz, thousands converged at the UC campus on Porter Meadow, defying university officials who had hoped to restirct access and reduce the crowd. "This is an event that's unsanctioned and unwelcomed by the university," says UCSC spokesperson Jim Burns. "It's based on an illegal activity that has become large in recent years. and we're attempting to send a signal that it's not welcome."

Check out their live footage from Santa Cruz as well.