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 National Wildlife Federation on Monday said that laws governing oil pipelines do not adquately protect the Great Lakes and its communities from oil pollution.
"Current laws leave the door open to future oil spills," said Sara Gosman, water resources attorney for the group's Great Lakes office and a lecturer att he University of Michigan Law School.
"Contrary to common perception, oil spills are an ongoing problem in the region," she said. "Federal and state laws should do more to prevent spills and protect our communities, economy and wildlife."
Ohio and the other seven Great Lakes states have 26,972 miles of hazardous liquid pipelines, according to federal data.
From 2007-2011, there were 277 pipeline accidents in the Great Lakes region that spilled more than 3.8 million gallons of mostly petroleum products and resulted in nearly $900 million in property damages, the agency said.
"Pipeline safety is a problem that has remained under the radar for too long," said Nick Schroeck of the Great Lakes Environmental law Center.
You can access the report and legal analysis at www.nwf.org/greatlakes.