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.
EnergyWire surveyed federal and state records for 2012 leaks and spills from oil and natural gas drilling.
It found 6,000 spills and mishaps, an average of 16 per day.
In the 12 states where comparable data exists, spills were up 17 percent, at a time when drilling activity in those states was up 40 percent.
The leaks added up to 15.6 million gallons of oil, fracking fluid, wastewater and other liquids spilled.
Click here to read the full story by EnergyWire reporter Mike Soraghan.