American Graffiti | Tamalpais High School Gym — One Day for the Whole Hop

The dance itself was shot forty miles south of Petaluma, in the boys' gym at Tamalpais High School on Miller Avenue in Mill Valley, on 1 August 1972. Lucas and his crew took the gym for a single day and got everything in it: the crepe paper, the band on the floor, Steve and Laurie's fight, the slow number that turns the whole room into one held breath. One day. The bathroom scene and the school exteriors were Petaluma's. The hop belongs to Tam.

Gyms are hard to shoot and easy to recognise. The film keeps the ceiling in frame — the trusses, the folded bleachers, the basketball backboards winched up out of the way — because that is what makes a school dance a school dance. Nobody has redecorated anything. They have hung streamers over a room built for volleyball, and everyone in it has agreed to pretend.

Tamalpais High opened in 1908 and has one of the handsomest campuses in Marin: low buildings under redwoods, with the mountain standing over the running track. It is an active school, so the gym is not a drop-in, but the grounds are walkable and the setting gives away something the film hides. The hop that feels like the beating centre of a small hot valley town was actually staged in a green coastal canyon, in one long August day, by a crew that had to be somewhere else the next morning.

Shoot date and building from location records for the production. Photograph is an illustrative school gymnasium floor via Pexels.