The Internet Archive maintains an enormous Live Music Archive of concert recordings, not all of them by the Grateful Dead.

https://archive.org/details/etree?tab=collection

In addition to Rusted Root and the Grateful Dead, you can stream or download a wealth of recorded live shows from bands like Little Feat, Blues Traveler, My Morning Jacket, Los Lobos, and the Smashing Pumpkins, as well as singer-songwriters like Warren Zevon, Elliott Smith, Jack Johnson, Robyn Hitchcock, and John Mayer.