One question does beg to be asked from this concert photo in the street. This would be considering that the Dead did not assemble a collage photo just for effect for the album liner. That is one large crowd, which blocked off many streets in San Francisco in about 1968. So apparently by then the Dead was mainstream enough to actually get a permit, and then they were able to estimate how big of a permit to apply for?
Nope, "Free Concert" on the back of a flatbed truck, promoted purely through underground newspapers, although local radio stations mentioned it when it started.
At the time the Haight was absolutely stuffed to the gills with wannabe hippies attracted by all the media hype about San Francisco's "Summer Of Love" and the "Hashbury" in general was largely taken over by pedestrian traffic anyway.
SF'S finest were used to the craziness and more than likely looked the other way because it was occurring as part of the activities of the Haight Street Fair and I suspect the Merchants who organized it would have been the "permitees"
Story here:
https://www.jambase.com/article/grateful-dead-play-free-set-at-haight-street-fair-in-1968
More than likely a police barricade of the streets was required, so through all this the Warlocks had suddenly become the man of the hour among local authorities for this festivity.
Very few people knew the band was ever called the Warlocks at that point(from the usual source):
"The first show under the new name Grateful Dead was in San Jose, California on December 4, 1965, at one of Ken Kesey's Acid Tests." ***
This was more of a "Woodstock" type thing where they just figured they'd throw a little freebie for the neighborhood and nobody realized how many people would show up when the news started leaking.
And while they were definitely local heroes in the Haight I wouldn't call 'em "mainstream" by any stretch, they had no top 40 AM airplay compared the Airplane, underground FM was in its infancy, and they didn't even break the top 100 until "Uncle John's Band" and "Truckin'" in '70.
They were "cult" status for sure, but oh, what a cult......
*** more amusing history trivia:
The Acid Test was actually intended to be a "Welcome Rolling Stones" after-concert party.
They were playing at the San Jose Civic Auditorium. They weren't as big, here, as the Beatles yet.
Kesey and crew assumed the band would get wind of the party somehow, and show up.
They actually thought like that.
But no such luck.