(February 13, 2017, 8:45 AM EST) -- DENVER — Colorado Attorney General Cynthia H. Coffman on Jan. 26 sent a letter to the commissioners of Boulder County, Colo., advising them that if the county government does not rescind its ban on hydraulic fracturing or if it “takes other steps to impede the efficient and responsible development of oil and gas resources,” she will take legal action against the county....