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.
New York state got a record 66,000 comments on hydraulic fracturing or fracking.
That is more public comment to the Department of Environmental Conservation than any other issue in its history.
The comments were filed between last September and January.
That's in addition to 13,000 additional comments that were filed earlier.
New York is studying a proposal to lift a moratorium and to proceed with drilling into the Marcellus shale, perhaps later this year.
Maryland is the only other state to ban hydraulic fracturing. It has launched its own study of the environmental and health impacts