The prose may be workmanlike and the book rutted with fault lines, but Dennis McNally’s behemoth of a Grateful Dead biography never sinks below fascinating, and it will likely set the standard for future treatments of the Dead. McNally, who is the Dead’s publicist and the author of the well-respected (and out-of-print) Jack Kerouac biography Desolate Angel, also has a PhD in history, and he puts it to great use as he spins the tale of the band’s first meeting, rocky start, steady ascension, and, ultimately, pathetic demise.

An expansive rogues’ gallery of guest stars is introduced along the way, from musicians’ intimates, crew members, sound personnel, and key business figures to ’60s anarchists, Black Panthers, sports figures and other celebrities, and politicians. McNally doesn’t shy from revealing the good and bad of his characters, but the ugly never casts much of a shadow. And as exhaustively detailed as his history is, the latter third of the band’s life gets shunted to a mere 100 pages at the end. These are micro-complaints, because the payoff is otherwise rich. But some of the omissions derail the great momentum the author spends hundreds of pages building, and they oversimplify a complex situation and a complicated group of people.

The story begins with the basic biographical data of the principal players — Jerry Garcia, Bob Weir, Bill Kreutzmann, Phil Lesh, and Ron " Pigpen " McKernan (second drummer Mickey Hart makes his appearance in due time) — in a pre–Vietnam San Francisco throughout which McNally looses the shimmering ghosts of the Beats. They’re important to the story, since he’s aiming to posit the Dead as a continuation of the legendary " movement, " the next logical step in the same open-to-everything, make-it-up-as-you-go ethos that dyes On the Road and The Subterraneans.

When we get to the Acid Tests (in which the late novelist Ken Kesey and his crew dosed everyone in sight while the Dead provided the soundtrack), that life-improv spirit gets jacked up several notches. Not only did it mandate the extended musical workouts that came to characterize the band (and gave them a glimpse of the musical vistas they’d forever try to reach), it also broke down all barriers between the Dead and those around them, instilling a philosophy that allowed the band’s crew members, sound people, lighting technicians, managers, accountants, and — yes — publicists to consider themselves de facto members of the Grateful Dead.

The shared philosophy and the sense of community give rise to several of the book’s more fascinating aspects. McNally describes a number of seriously democratic band meetings, one in particular where a dissenting vote from a custodian vetoes a proposition made by impresario Bill Graham. Grateful Dead Records is founded and envisioned as an alternative to the industry; there’s even a not-quite-kidding proposal to distribute the records via ice-cream trucks. And a huge off-kilter corporation is created to handle the archives, merchandise, and ticket sales of what was once America’s highest-grossing touring band. A Long Strange Trip also examines the symbiotic relationship among the musicians, crew members, and sound technicians, whose obsessive quest to provide pristine sound parallels the Dead’s search for the mystical note.

But it might be a publicist’s instinct for spin control or — if McNally can rightfully claim to be part of the family — some intra-band omertà that prevents him from scraping too much dirt from under the group’s collective fingernails. Two 1996 books, for instance, conjured more malevolent aspects of the Dead anima: the pages of manager Rock Scully’s Living with the Dead were alternately dusty from cocaine and sticky from heroin, and Robert Greenfield’s Dark Star made you want to dig Garcia up and kill him again for his horrible parenting and spousal skills and wicked self-destructive bent. Not that the story of the Dead needs to descend to tabloid levels, but the foundation of any great bio lies in the contradictions that make its subject interesting.

There are other odd choices ranging from small to significant. The death of long-time keyboardist Keith Godchaux is dispensed with in a parenthesized half-sentence. Garcia’s death comes seven pages from the end. And there’s no mention of how the Deadhead cult sprang up and developed. It’s obvious that McNally doesn’t plan a sequel, so what’s missing sets the stage for future Dead histories. But what he has given us is authoritative, compelling, and the best inquiry yet into a phenomenon we’ll never see again.

Dennis McNally reads from A Long Strange Trip on Tuesday, August 20, at 7 p.m. at the Harvard Coop. Call (617) 499-2000.