Ohio has issued 431 permits for drilling horizontal wells into the Utica shale.
To date, 178 of those wells have been drilled, according to the Ohio Department of Natural Resources' Division of Oil and Gas Resources Management.
A total of 36 of those wells are in production, as of Oct. 27.
There are 24 rigs operating in eastern Ohio.
A total of 12 state permits were issued last week: six in Carroll County, two in Columbiana, three in Harrison and one in Mahoning.
Carroll County is No. 1 in Ohio with 149 permits.
Columbiana has 58 and Harrison has 51.
Jefferson has 31; Guernsey, 24; Monroe, 18; Mahoning, 14; Portage, 14; Stark, 13; Noble, 13; and Belmont, 11.
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.