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.
West Virginia is expected to get 13 or 14 earthquake monitors this summer, West Virginia Public Radio reported last week.
The stations will remain in place for two years under the EarthScope program.
It is a venture of the Incorporated Reserach Institutions for Seismology and the National Science Foundation.
The program got under way in 2004 with the installation of small seismic stations on a grid across the United States. The program is moving the array from west to east.