Residents of Ann Arbor, Mich., will be familiar with Hash Bash, the annual, smoke-filled rite of spring set for the first Saturday of the month. This year, after voters legalized recreational marijuana statewide in November, the event, which brings thousands to the campus of the University of Michigan, will have a decidedly celebratory atmosphere. But even with that political success, Hash Bash, which got its start in 1972, isn’t going to disappear anytime soon.

Part of the reason, as organizers have pointed out, is that there are still plenty of drug laws to protest. But the real reason Hash Bash will live on is less political than cultural.

For outside observers, the mass of humanity, the barely audible speeches, and the ubiquitous smell of marijuana characterizing the event adds little to the town and perhaps even distracts from the political message of reforming drug laws. But the event was never simply a call to political action, never mind what the student organizers write on the forms submitted to the university. It is a tradition baked into the local culture, drawing on distant, hazy, rose-tinted memories of Rainbow Gatherings and the John Sinclair Freedom Rally.

A student writing for the Michigan Daily in 1989 aptly described the Bash as Ann Arbor's version of a historical festival complete with "spectacular reproductions" of hippies:

So once every year or so, [Ann Arbor] gets a little misty-eyed. It goes into the attic, opens the trunk, dusts off its MC5 albums, reads through its newspaper clippings, and calls up a few old friends to come over, get wasted and talk about how great we was then. They call it the Hash Bash. It rhymes.

Thirty years later, the Bash is still a local festival deeply rooted in history — or at least a particular telling of the past. In fact, it is that anachronistic idea of protest that is likely the key to Hash Bash's longevity.

As early as 1982, for example, the Ann Arbor News characterized it as “an idea whose time has gone, a dinosaur, a concept that went from outrageous to quaint without ever quite passing through respectability.”

But the “quaint” nature of the event, the nostalgia and the connection to the past, is still a powerful draw for attendees. The Bash is a porthole to an imagined past, easier to use than the phone booth in "Bill and Ted’s Excellent Adventure" and less refined than Walter Benjamin’s lyrical flânerie. The collective memory of the event, hazy though it might be, recreates the feeling of being part of a movement, the legendary “Woodstock nation," even for attendees who are too young to understand the power of the reference.

For Hash Bash, that blend of tradition and nostalgia means that even if no one formally organized the event, no one brought posters, and there were no speakers calling for reform from the makeshift stage of the Hatcher Graduate Library steps, people would still show up just as they have been doing for decades. Marijuana legalization didn’t change that.