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.
The Congressional Research Service has issued a new 21-page report on hydraulic fracturing and chemical disclosure requirements.
The report looks at chemical disclosure laws in states where shale drilling is common.
At present, there are no federal chemical disclosure laws tied by hydraulic fracturing or fracking.
The report was prepared for members and committees of Congress.
The authors were Brandon J. Murrill and Adam Vann.
Click here to read the report.