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.
Germany is set to oppose hydraulic fracturing or fracking, Spiegel reported on Monday.
The German newspaper reported that Environment Minister Norbert Rottgen and Economy Minister Phillip Roster were "very skeptical" of the process to free up natural gas, oil and wet gases like butane, ethane and propane.
That opposition is expected to put a stop to fracking in Germany.
Environmental groups have been mobilizing to stop ExxonMobil's fracking plans in shale in northern and eastern Germany.