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.
Organizers on Wednesday announced plans for a major anti-fracking rally on July 28 in Washington, D.C.
The event will run from 10 a.m. to 2 p.m. on the West Lawn of the U.S. Capitol.
It is called Stop the Frack Attack and is the No. 1 event in a National Day of Action against hydraulic fracturing or fracking in drilling for natural gas.
It is being supported by grass-root groups in Ohio and 12 other states.
"The President and Congress need to hear the truth about the destruction of irresponsible fossil fuel extraction directly from drilling communities," said Kari Matsko, an Ohio member of the National Day of Action advisory committee.
"Gas isn't clean and drillers always put their profits ahead of the health of American families. This has to stop, and we expect our elected officials to make sure it does," she said.
Said Wyoming rancher John Fenton, also on the advisory committee, "Dirty drilling isn't a state or regional problem. It's a national problem."
Added Calvin Tillman of Texas: "Drilling that harms our health, water and air isn't acceptable. Americans deserve better, and we expect to get it."
The event is being billed as the nation's largest anti-fracking rally.