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.
The U.S. Environmental Protection Agency faces a Tuesday deadline to impose tighter limits on air emissions from natural gas-oil production under a federal court consent decree.
Both sides in the debate are still doing a lot of posturing.
A month ago, the American Petroleum Institute released a report that said drilling for natural gas would drop by as much as 52 percent, if the new federal air rules are adopted.
The report by Advanced Resources International said natural gas production would decline by 11 percent and oil production by 37 percent.
The federal government would not get $8.5 billion in royalties and state governments would not collect up to $3.2 billion in severance taxes, the report said.
At least one environmental group, the Natural Resources Defense Council, says those numbers are incorrect and that tighter air emissions are needed to protect human health.
You can find that group's position here.
The EPA's proposed rules would cut emissions of volatile organic compounds by 25 percent and VOC emissions from new or modified fracked wells by almost 95 percent.
The rules also propose to limit sulfur dioxide and air toxic emissions from wells, gas transmission pipelines and storage facilities.