The Elm Coulee Oil Field

By editor

Sidney, Richland County, Montana

You want to hear about oil? Well, pull up a chair and I’ll spin you a yarn about the Elm Coulee Oil Field, a place deep in the dirt of northeastern Montana where the black gold suddenly began to flow just at the dawn of the 21st century. Now, the Bakken Formation, where Elm Coulee sits like a sleeping giant, wasn’t a new discovery in 2000. Far from it. The name Bakken comes from a North Dakota farmer named Henry Bakken. In 1951, some drillers poked around on his land near Tioga and struck oil in a layer of dolomite rock sandwiched between two shales. This was the Late Devonian age, about 350 million years ago, when the earth looked very different and the sea covered much of what we now call the Williston Basin.

The Williston Basin itself is a curious beast -- a broad, irregular bowl-shaped depression that stretches across eastern Montana, western North Dakota, and parts of South Dakota and Canada. Over hundreds of millions of years, this basin collected sediments up to 16,000 feet thick. It had the right ingredients for oil and gas: organic-rich black shales that cooked under pressure to make oil, porous layers of sandstone and dolomite to hold it, and traps formed by faults and folds that kept the oil from running away. There was oil here, alright, but it had been hiding and playing coy for decades.

Then came the Elm Coulee Oil Field, discovered in the year 2000, sprawling over roughly 750 square miles of Richland County. The oil lies deep, between 8,500 and 10,500 feet down. The oil-bearing layer itself is a mere 45 feet thick, which sounds like a sliver, but it’s enough to make a difference when it’s under that much pressure and heat. The big change that unlocked Elm Coulee’s riches was technology--horizontal drilling combined with hydraulic fracturing, or fracking, for those who like their science with a bit of a bang.

Before Elm Coulee came along, Montana’s oil production was modest, a steady trickle rather than a gusher. But starting in 2001, the field nearly doubled the state's output in just a few years. By 2013, nearly 150 million barrels had been pulled from the ground. To put that in perspective, each barrel is 42 gallons, so that’s a lot of black liquid coursing out of a rock no thicker than a two-story building.

The Bakken Formation across the Williston Basin is estimated to hold over 500 billion barrels of oil in place. That’s an eye-popping figure, but don’t let it fool you. Only about 7 billion barrels are considered recoverable with current technology, and even that number has been the subject of lively debate. The geologist and energy economist M. King Hubbert, famous for predicting the "peak oil" concept, once noted, “The volume of oil in place is not the volume of oil we can get out” -- a caution that the Bakken’s riches come with limitations, and the dance between geology and technology is ongoing.

The story of Elm Coulee isn’t just about rocks and oil. It’s about people, money, and the machinery of industry that turned a sleepy agricultural county into a hive of activity. Sidney, the nearby town, saw its population swell as workers, engineers, and speculators poured in. Land prices soared as lease agreements and mineral rights changed hands for sums that would have made Henry Bakken’s head spin. Banks in Sidney and beyond scrambled to finance drilling operations, while railroads and pipelines hustled to move the oil out of this once-quiet corner of Montana.

The Montana Department of Transportation erected a historic marker at Elm Coulee that succinctly captures the geology and significance of the field, but it’s the economic ripples that tell a richer tale. In 2006, the Montana Oil and Gas Conservation Division reported that Richland County’s tax revenues jumped from under $2 million in 2000 to more than $30 million by 2005, thanks largely to Elm Coulee. Local businesses thrived, schools collected more funds, and the county’s profile rose.

But the boom carried its own riddles. Environmental concerns about fracking’s impact on water supplies began to surface, and debates over the longevity of the field’s production kept investors on edge. The initial excitement was tempered by the reality that oil prices fluctuate wildly, and the Bakken’s geology is notoriously variable. Some wells fizzled quickly, while others produced steadily. It was as if the earth was willing to share its wealth, but only on its own terms.

One of the pioneers behind the Elm Coulee discovery was geologist Rick Kennedy, who, in interviews, described the breakthrough with a mix of disbelief and dry humor: “We thought we were onto something big, but even then, the scale of it was hard to grasp. It’s like finding a book in a foreign language and realizing it’s a bestseller.”

The Elm Coulee Oil Field’s sudden rise also exposed the gap between optimistic projections and the hard numbers of production. Industry reports sometimes spoke in terms of billions of barrels recoverable, stirring visions of a new oil empire in the northern plains. Yet, as the years passed, it became clear that the Bakken, while rich, was not a bottomless well. The field’s peak production came in the early 2010s and has since declined, a reminder that oil booms are often followed by busts or slowdowns.

Still, Elm Coulee changed the face of Montana’s energy landscape and brought the state into a new era of oil development. It bridged old frontier oil stories from the early 20th century with modern technological marvels. And as the oil flowed, so did the hopes and worries of those who lived in the shadow of the wells.

In the words of Montana Governor Judy Martz in 2003, “The Bakken formation has the potential to change the economic landscape of eastern Montana for generations.” Well, it did change the landscape, though not without bringing the usual mix of fortune and frustration that comes with striking it rich.

So, when you think about the Elm Coulee Oil Field, remember it’s not just a patch of dirt with some oil under it. It’s a chapter in the ongoing story of mankind’s appetite for energy, the gamble of geology, and the ever-turning wheels of industry. And maybe, if you listen close, you can hear the murmur of those ancient seas that laid down the rocks, long before the first derrick ever creaked into place.

See also

• The Elm Coulee Oil Field at Sidney, Richland County
• Coal, Oil, and Natural Gas at Glendive, Dawson County
• Northern Pacific Railroad in Redwater Valley at Circle, McCone County