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.
A poll of Ohioans shows that seven out of 10 want the hydraulic fracturing or fracking process used in natural gas drilling halted until the issue can be studied further.
Those surveyed in the Quinnipiac University survey said they feel that the economic benefits of fracking outweighed the risks.
In the statewide survey, Ohioans said, by a ratio of 72 to 23, that fracking should be halted until it can be analyzed further.
The U.S. Environmental Protection Agency is looking at fracking, but a final analysis is not expected until 2014.
The industry says the practice is safe and has been used for decades. Critics say they are worried by spills and leaks at the surface contaminating drinking water.
Ohioans are conflicted on fracking, said Peter Brown, assistant director of the Quinnipiac University Polling Institute.
Ohioans feel that the economic boom from drilling outweighs the risks by a 64-29 ratio and the possibility that the drilling will bring jobs to Ohio by a 85-11 ratio,.