After 21 years, nine studio albums, nearly two dozen official live offerings and countless bootlegs, the jam band Phish will soon be history.

Guitarist Trey Anastasio announced that the quartet will split up following its summer tour via a post on the band's Web site Tuesday. Anastasio, drummer Jon Fishman, keyboardist Page McConnell and bassist Mike Gordon discussed the future of the band on Friday and mutually reached the decision that they should retire now, while the band was still on a high note.

"We all love and respect Phish and the Phish audience far too much to stand by and allow it to drag on beyond the point of vibrancy and health," Anastasio wrote. "We don't want to become caricatures of ourselves, or worse yet, a nostalgia act."

Although never quite feeling comfortable in the role, Phish were dubbed by many as successors to the Grateful Dead for their penchant for improvisational live shows -- which are more extravaganzas than mere concerts -- and extended jams. Thus, they're often credited with pioneering the jam-band scene, which has spawned the likes of moe., the Disco Biscuits and the String Cheese Incident, who are on this year's Lollapalooza trek.

The band's final tour is scheduled to start with a pair of shows in Brooklyn, New York, beginning June 17, two days after their new album, Undermind, is released. Two-night stays are slated for four other cities, followed by a single performance in Camden, New Jersey, on August 12. Phish's career will close with two shows in Coventry, in their home state of Vermont, on August 14-15.

Anastasio wrapped up his post by reiterating that this is indeed the end and not to be confused with the two-year hiatus the band took in 2000, which he described as "the last attempt to revitalize ourselves." In that time, each member splintered off into various side projects. Anastasio formed Oysterhead with Primus' Les Claypool and the Police's Stewart Copeland, and he released a self-titled solo album in 2002; Fishman formed Pork Tornado; McConnell hooked up with Vida Blue; and Gordon played with Col. Bruce Hampton and also released a solo LP.

"It's been an amazing and incredible journey," Anastasio concluded. "We thank you for all the love and support that you've shown us."