Ohio has topped 600 Utica shale permits, according to latest update from the Ohio Department of Natural Resources.
Ohio now has 605 permits, of which 297 wells have been drilled.
A total of 89 of those wells are in production, as of April 13.
A total of 32 drilling rigs are at work in Ohio.
The latest permits are nine in Carroll County, three in Harrison County and one in Noble 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.