The Avengers star and Callicoon resident co-hosted the New Yorkers Against Fracking concert with Academy Award-winner and Ulster County resident Melissa Leo during the evening against hydrofracking.
The 44 year-old actor, a longtime opponent of hydraulic fracturing, co-founded an anti-fracking advocacy organization, Water Defense, to educate and stop fracking in New York State.
The concert and reception are a fundraiser for New Yorkers Against Fracking, a coalition of hydrofracking critics launched earlier this year to push for a ban on the technique. The fundraiser featured many famous New York residents such as upstate New York native Natalie Merchant, Citizen Cope and Medeski Martin & Wood.
In March, Mark appeared on the Colbert Report to discuss how he became an anti-fracking, clean water activist after seeing the technologies' detrimental impact on communities in Pennsylvania.
More photos of Mark Ruffalo at the anti-fracking rally after the jump!
PHOTO CREDIT: CHET GORDON/Times Herald-Record