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.
According to the Environmental Defense Fund, Ohio passed the most comprehensive natural gas bill, but it didn't go far enough.
Click here to read the blog post by the eco-group's Matt Watson on why natural gas extraction remains a threat to the health of Ohioans and the environment.
Watson testified in support of Senate Bill 315, although he urged Ohio legislators to do even more.
In a related move, the grass-roots group Don't Frack Ohio called S.B. 315 "one of the worst fracking laws in the nation."
It said: "The bill heading to Gov. John Kasich's desk fails to reinvest in Ohio communities, fails to adequately protect them from toxic impacts of the fracking industry and fails to help Ohio adress the growing climate chyange."
The bill "means that Ohio will allow bigger health and safety loopholes and ask the gas industry to pay less than almost any other state in the country,"
The bill is awaiting Kasich's signature.
Don't Frack Ohio is supporting a June 17 protest in Columbus.