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.
Ohio has approved 858 Utica shale permits, through Aug. 24.
Of that total, 514 wells have been completed. A total of 125 wells are in production.
A total of 36 drilling rigs are working in Ohio, said the Ohio Department of Natural Resources.
Fifteen new permits have been approved: three in Columbiana, one in Guernsey County, four in Harrison County, five in Noble County and two in Washington County.