The split news has fuelled rumours suggesting the two veteran rockers are planning a Dead reunion to mark the band's 50th anniversary next year (15).
The break-up has been confirmed on Furthur's website in a post that reads: "To our loyal Furthur fans and members of the Furthur community at furthur.net, we'd like to thank you for a terrific ride. We'll be closing up shop at furthur.net, and heading onward.
"Thanks for making the Furthur community a great place to hang out, and for coming out to the shows. We'll all be keeping very busy over the foreseeable future, and it's time to let Furthur take a bow. We enjoyed the ride more than we can possibly express."
Weir and Lesh formed Furthur in 2009.