Bob Weir's jam band outfit Ratdog, a group that focuses mainly on the songs and style of Weir's former band the Grateful Dead, played a marathon set on day two of Mountain Jam last night, including a second-set appearance by Gov't Mule's Warren Haynes.

Haynes sat in on an epic version of 'Dark Star,' wich began with a knotty, complex jam and dwindled, after many mellow minutes, out into the ether. Rootsy singer Jonathan Wilson also took a turn on stage, on late-period Dead tune 'West L.A. Fadeaway' and a cover of the Jerry Garcia Band's 'Don't Let Go.'

Other highlights from the sprawling performance included an energetic 'Me and My Uncle' near the end of the first set, the classic 'Sugar Magnolia,' and a 'Johnny B. Goode' encore that featured another appearance by Haynes.

Earlier in the evening, Weir sat in on with the Avett Brothers, joining them for George Jones' "The Race is On" and the Avetts' 'Go to Sleep.'