Bob Weir’s Life Beyond Dead : Rock: With Garcia and Co. on sabbatical, the guitarist is able and willing to stretch out in musical and environmental endeavors, including a stop at the Coach House tonight.

The Grateful Dead is one of rock’s most durable acts, having been together for the better part of 30 years now.

The group’s longevity probably is due in part to the various side projects its members have had to vent creative steam in more diverse directions. Singer-guitarist Bob Weir has been perhaps the most active member of the Dead in these ventures.

Through solo albums including “Ace” and “Heaven Help the Fool,” and part-time side bands Bobby & the Midnites and Kingfish, Weir has never been content to idle when the Dead takes one of its frequent sabbaticals.

His main side project for the last few years has been performing with bassist Rob Wasserman, a virtuoso known for his solo work and for stints with Van Morrison, Rickie Lee Jones and David Grisman, among others. The duo appears tonight at the Coach House in San Juan Capistrano.

“We’re pretty fast on our feet,” Weir said in a recent telephone interview from his Bay Area home. “There’s only two of us, so if we decide we want to make a quick left turn, we can do that. Wasserman is a whole band by himself.”

Weir said the duo performs cuts off his solo albums, a few Grateful Dead numbers and a variety of blues, jazz and R & B standards. The twosome has been working on and off in the studio the last few months, laying down tracks for an album to be released at an as-yet-undertermined point in the future.

Weir seemed particularly excited about the chance to stretch out on the guitar and take a more active role on the instrument than he normally has a chance to do with the Dead.

“I can’t play as many notes with the Grateful Dead as I can with Wasserman,” he said. “Most often, a chord is only going to be two or three notes in the Grateful Dead, because that’s all that’s going to punch through in the band. Anything more than that would get lost and turn to mud.

“In the Dead, I’ve developed a completely different kind of guitar playing than (lead guitarist Jerry) Garcia, which is what I wanted. I never wanted to be a lead guitar player. I do it now and then sort of as a lark, but that’s not my passion. My passion is shaping a song, and with Rob, I can play full chords and layer stuff a lot thicker. It’s a lot of fun.”

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Aside from music, Weir has been a highly visible activist on environmental issues in recent years. He founded and largely pays for the Further Foundation, which he said “addresses environmental, educational and public-health concerns around the world.”

Last year, he wrote an opinion piece for the New York Times, railing against a bill designed to approve massive deforestation in the northern United States. The bill never passed, and Weir believes that was partly due to his efforts.

“I’ve basically come to the realization that part of working for a living today is working for a world in which to live, because otherwise, it’s no longer a given,” he said. If we don’t stop our ruinous ways, we will end life on this planet in short order.”

Weir and his sister Wendy are also award-winning authors of a children’s book, although neither one has any children.

“That’s something that just sort of happened,” said Weir. “My sister kind of crowded me into doing it, and now I enjoy it. The book we have out now is called ‘Panther Dreams,’ and it’s the story of a kid who lives in the African rain forest, and he goes out and has a profound experience there. We’re working on another one, about a kid who lives in the South Pacific.”

No matter what Weir embarks upon--musically or otherwise--he will always be best known as a member of the Grateful Dead.

A love-’em or hate-’em group that epitomizes all the generosity of spirit and all the wretched excess of the ‘60s, they inspire unflagging devotion from some, disdain from others.

“I don’t know why that is, but both extremes give me the creeps,” said Weir.

At times, the Deadheads have become troublesome even to the group, as their huge numbers and sometimes cavalier attitudes toward the communities they all but take over has resulted in the group being banned from a number of venues, including its former roost in Orange County, Irvine Meadows Amphitheatre.

For his part, Weir seemed ambivalent about this fervent brand of fandom.

“If they’re just devoted, that’s fairly harmless,” he said. “But if they’re making a mess of their lives--or other people’s lives and property--that’s another story.

“The ones who exhibit an ‘I don’t give a damn, I’m just out to have a good time’ attitude, I can’t get with. Never have. None of us have every been able to hang with that,” he said.

“It’s nothing we ever promoted, and I don’t know where it came from. But I must say that those people are a small--if unfortunately visible--minority.”

* Bob Weir and Rob Wasserman, with opening act Susan James, perform at 8 tonight at the Coach House, 33157 Camino Capistrano in San Juan Capistrano. $29.50. (714) 496-8930.