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 U.S. Geological Survey has issued its report of water availability in three reservoirs in east-central Ohio.
The report looks at Atwood, Leesville and Tappan lakes in the Muskingum Watershed Conservancy District.
The report by USGS staffer Gred Koltun was commissioned because drillers were seeking water from those lakes to frack Ohio's Utica shale.
The 33-page is a statistical analysis of water levels in the three reservoirs.
Koltun looked at three different pumping scenarios in doing his analysis.
The report offers no conclusions, just a statistical analysis, said USGS staffer David Straub.
That analysis indicates that water levels are the lowest from June to October and again in February when the lakes are refilling after having been lowered for the winter.
Water is most abundant in the spring and again in the late fall when the reservoirs are lowered for the winter.
The district is satisfied with the USGS findings and considers the report to be helpful data, said spokesman Darrin Lautenschleger.
The report increased the district's knowledge about water availability and confirmed that there are seasonal trends in water availability, he said.
The district has contracted with the USGS to conduct a similar analysis of its seven other reservoirs. That analysis is scheduled to be completed in 2014, he said.
Click here to see the first USGS report.