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.
From the U.S. Energy Information Administartion:
U.S. proved crude oil reserve additions in 2011 set a record volumetric increase for the second year in a row, according to newly published estimates in EIA's U.S. Crude Oil and Natural Gas Proved Reserves, 2011. Natural gas proved reserve additions fell short of setting a record, but still ranked as the second largest annual increase since 1977. Crude oil reserves rose 15% (almost 3.8 billion barrels) to the highest level since 1985, and natural gas reserves were up almost 10% (31.2 trillion cubic feet).