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 Ohio Environmental Protection Agency has finalized final air general permits to cover production operations at shale gas well sites.
Applicants who meet qualifying criteria, terms and conditions of the general permit can expect to receive EPA approval within weeks of applying, the agency said.
The general permit covers a variety of emissions sources found at most shale gas well sites including from internal combustion engines, generators, dehydration systems, storage tanks and flares.
It contains emission limits, operating restrictions and monitoring, testing and reporting requirements.
Here's where to go for more information on the state permits.