Chesapeake Energy Corp,the Oklahoma-based firm is the No. 1 driller in Ohio.
Rig Count Interactive Map by Baker Hughes, an energy services company.
Shale Sheet Fracking, a Youngstown Vindicator blog.
The Ohio Environmental Council, a statewide eco-group based in Columbus.
Earthjustice, a national eco-group.
People's Oil and Gas Collaborative-Ohio, a grass-roots group in Northeast Ohio.
Concerned Citizens of Medina County, a grass-roots group.
No Frack Ohio, a Columbus-based grass-roots group.
Fracking: Gas Drilling's Environmental Threat by ProPublica, an online journalism site.
Pipeline, blog from Pittsburgh Post-Gazette on Marcellus shale drilling.
Allegheny Front, environmental public radio for Western Pennsylvania.
Anti-fracking activist Sandra Steingraber is done with the Sierra Club.
The visiting professor at Ithica College, author, ecologist and cancer survivor is unhappy that the Sierra Club accepted $25 million from Chesapeake Energy Corp. from 2007 to 2010.
That news broke in February in Time magazine.
She has written a personal letter to the Sierra Club that ran on the Orion magazine blog. Click here to read it.