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.
Hydraulic fracturing or fracking may cause new water problems in the American West.
Drilling is growing in places where water supplies are already stretched thin.
The nonprofit group Ceres, in a report released on Wedneday, looked at 25,450 fracked wells and found that 47 percent are in areas that face high or extremely high water stress.
In those areas, 80 percent of the available fresh water is already being used in homes, farms and businesses.
The spread of drilling could lead to increasing competition among drillers, farmers and homeowners for water, said spokeswoman Monika Freyman.
It is already starting to happen and drilling companies may win because they can afford to pay more for water than the others, she ssaid.
Click here to see the full report.