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 has 75 inspectors to oversee natural gas and oil drilling in the state, reports Columbus Business First.
Thye magazine says the agency wants to double that number to 150 by the first quarter of 2013.
The agency would use fees and the proposed severance tax to fund its expanded operation.
Ohio has paid for new staffers with money from a fee on injection waste from Pennsylvania that is shipped to Ohio for disposal.
Ohio has about 50 wells drilled into the Utica shale. That number could grow to 2,250 by 2015, according to state estimates.