On March 22, 1976 —  The California Angels’ groundskeeper finds hundreds of marijuana plants growing in the outfield at Anaheim Stadium. The culprits? Most likely rock fans who attended a recent performance at the stadium by The Who.

Only ten years old at the time, The Big A recorded its largest crowd ever when 55,000 stomping and screaming fans jammed the baseball facility to see Pete Townshend and Roger Daltrey play their classic hits, leaving ten tons of litter for stadium workers to clean up in its aftermath.

More than just litter, stadium officials estimated to the LA Times that about 100 marijuana plants sprouted in the outfield as a result of the concert. Mayor William J. Thom quipped, “The economic situation at the stadium has not reached such a perilous point that we have to resort to growing marijuana.”

As manager of Anaheim Stadium, Tim Leigler, put it at the time, “What we’ve got out here is grass in the grass.”