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 Chillicothe Gazette reported on Wednesday that interest in Ross County in southern Ohio is growing among drillers.
Rhonda Reda of the Ohio Oil and Gas Energy Education program spoke in Ross County and said drilling will likely spread to the south and the west.
There are signs that drillers are getting interested in Ross County, reported Ross County Recorder Kathy Dunn, the paper reported.