The September 13-14 event will be held on five stages at Red Rocks Amphitheatre in Morrison, Colo.
Artist joining Devotchka on Saturday include Silversun Pickups, Neko Case, Vampire Weekend, Del tha Funky Homosapien, Cut Copy, The Fratellis, A Place to Bury Strangers, Blitzen Trapper, The Morning Benders and many more.
On the Sunday bill with Justice are TV on the Radio, Band of Horses, Sharon Jones & The Dap Kings, CSS, The Avett Brothers, Tokyo Police Club, The Heavy, The Cribs, The Ting Tings and others.
A complete roster is available at the festival's web site, along with daily lineups.
Tickets, priced at $59.50 for single-day and $110 for two-day passes, go on sale Friday May 2 at MonolithFestival.com and Ticketmaster.com.
VIP gold passes, which are $225 and include reserved soundboard seating, VIP parking, pre- and post- show party access an more, also go on sale May 2 exclusively at MonolithFestival.com.