According to the company's profile, Bronco operates rigs in North Dakota. According to the NDIC active drilling list, it looks like Bronco has about ten (10) rigs in North Dakota.
Chesapeake has said it wants to own about two-thirds of the rigs it operates under its drilling program. It will integrate Bronco into its Nomac Drilling unit, which currently owns 95 drilling rigs.Someone opined in a comment just a few days ago that Chesapeake will enter North Dakota. This is a very small piece of Chesapeake (buying Bronco) but technically that has now happened, assuming Chesapeake doesn't divest itself of some of the Bronco assets.
Right now, it appears (at least to me) that Bronco is a contract driller and does not go after permits in the Bakken itself. It will be interesting to see if Chesapeake eventually acquires acreage in the Bakken.
Bronco's profile emphasizes that it supports both oil and natural gas exploration and production companies.