Warren Haynes fourth annual Mountain Jam Music Festival has expanded its roster of performers. Bob Weir & RatDog and Dr. Dog will make their first appearances at the festival which will take place at New Yorks Hunter Mountain from May 30- June 1. Umphrey’s McGee, which performed at Mountain Jam 2007, is another addition to the line-up along with Pete Francis (Dispatch) and Larry McCray. They join a roster that already includes Haynes’ Gov’t Mule as well as Michael Franti & Spearhead, Medeski, Scofield, Martin & Wood, Citizen Cope, Drive-By Truckers, Dark Star Orchestra, Ivan Nevilles Dumpstaphunk, Galactic, Grace Potter & the Nocturnals, Sharon Jones & the Dap-Kings, JJ Grey & Mofro, The Greencards, Jim Weider, The Felice Brothers, Jackie Greene, Pnuma Trio, and Lotus. For the first time, Mountain Jam will also host outdoor late night performances by artists such as Galactic and the Dark Star Orchestra on Friday and Saturday nights. These starlit performances will complement the festivals already popular late night offerings by dance bands like Lotus and the Pnuma Trio in the enclosed Hunter Mountain Lodge. Mountain Jam passes are now on sale at the Mountain Jam and Gov’t Mule websites.