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.
Texas-based Halcon Resources says it plans to invest $200 million in 2013 in the Utica shale in eastern Ohio and western Pennsylvania.
The company, based in Houston, has plans for 20 to 25 wells in 2013. The first wells will be drilled in April.
The first 10 wells will help delineate where later wells will be drilled.
The company has about 130,000 acres in the Utica shale in the two states.
Click here to read more from The Business Journal that is based in Youngstown.