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.
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.