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 Department of Natural Resources reports that Ohio has approved 567 Utica shale permits, as of March 9.
Of that total, 268 wells have been drilled and 76 wells are in production.
A total of 35 rigs are working in Ohio.
A total of 18 new permits were approved: 10 in Carroll County, three in Belmont County, one in Columbiana County, one in Harrison County, two in Monroe County and one in Tuscarawas County.