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.
Fracking for natural gas is not clean, green energy, say Greenpeace director Phil Radford and actor Mark Ruffalo at CNN.
The two write: "Even the heads of fossil fuel companies read the polls. They know the majority of Americans see global warming as an imminent threat and a clear sign that the way we use energy must change. But instead of offering the solar and wind choices America wants, fossil fuel companies like Shell, Exxon and Duke are offering what might be their most disastrous bait and switch yet: natural gas.
"The bait? Burning natural gas is "clean" because it produces less carbon pollution than burning oil and coal. The switch? The catastrophic pollution caused when companies like Exxon fracture the earth -- commonly called fracking -- to get natural gas out of the ground."
The entire CNN article is here.