Rocky Mountain oil search yields $14.7 billion in deals over 18 months

The lure of oil beneath the Western Plains — from North Dakota to Colorado — has led to a record $14.7 billion in mergers and acquisitions since the start of 2011, according to an analysis by accounting and consulting firm PricewaterhouseCoopers.

"Since 2006, deals have been trending up until they reach a new peak," said Rowena Cipriano-Reyes, a Denver-based partner with PwC's energy practice. The study included 2011 and the first half of 2012.

The targets for this deal-making have been two potentially oil-rich geological formations — the Bakken in North Dakota and the Niobrara in Colorado and Wyoming.