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.
MarkWest Energy Partners LP on Monday said it will buy Keystone Midstream Services LLC for $512 million to boost its processing operations in the liquids-rich Marcellus shale.
Keystone, owned by Rex Energy Cor, Sumitomo Corp and Stonehenge Energy Resources LP, has assets in Butler County, Pa, including two cryogenic gas processing plants, Reuters reported.
MarkWest -- a master limited partnership engaged in gathering, transporting, and processing natural gas -- anticipates gas volumes from Keystone to grow from the current rate of 40 million cubic feet per day to 170 MMcfd at the end of 2013, and to about 350 MMcfd by 2016, the news outlet said.
The limited partnership said it plans to invest up to $500 million over the next five years to support Rex Energy's drilling program in the region and expand its gathering and processing facilities, Reuters said.
As part of the investment, MarkWest also proposes to extend its planned natural gas liquids pipeline from its Houston, Pa., complex into Butler County.