The Merry Pranksters' Furthur bus anchors "Forever Grateful, Golden Gate Park," opening Sept. 5 at the County Fair Building. The move for a broke Deadhead: a free Grahame Lesh & Friends set on Monday, Sept. 7.

Furthur — Ken Kesey's psychedelic touring bus, the rolling headquarters of the Merry Pranksters and their 1960s "acid tests," still wearing the misspelled destination sign it took its name from — is back in San Francisco after decades parked on the Kesey family farm in Oregon. It's the bus Neal Cassady once drove cross-country to the 1964 World's Fair, and it hasn't been in the city in about half a century.

Now for the part that matters if you want to stand next to it. The bus headlines "Forever Grateful, Golden Gate Park," open Saturday, Sept. 5 through Oct. 25 at the park's County Fair Building, the big hall near 9th Avenue and Lincoln on the Inner Sunset edge. The presenting Haight Street Art Center↗ (external source, opens in a new tab) says a second artifact never shown publicly before — Jerry Garcia's BMW — sits alongside it, plus a live liquid light show and roaming performers from Third Rail Projects. It's a ticketed show; tickets are on sale now through the art center.

If you'd rather not pay, aim for the Monday. Opening weekend caps with Grahame Lesh & Friends playing free on Sept. 7 in Robin Williams Meadow, next door to the exhibition, as Local News Matters reported↗ (external source, opens in a new tab) when the city announced the run — no wristband, no lottery, just walk up. Take the N-Judah to 9th and Irving and skip the car; Inner Sunset parking on a holiday Monday will eat your afternoon. My two-hour version: catch the meadow set, then drift over to see the bus.