Rocky Mountain (PADD 4) diesel price

Colorado, Idaho, Montana, Utah and Wyoming make up PADD 4, Rocky Mountain, the smallest of the five districts by population and by diesel volume sold. A handful of refineries serve this large, sparsely populated area with little pipeline connection to neighboring districts, so the market runs closer to self-contained than connected, and that combination of thin competition and long hauls to scattered towns usually keeps prices a bit above the national average, a real but modest premium next to the West Coast's.

Because so few refineries supply the whole district, an outage at any one of them matters more here than in a deeper market. Oil and gas drilling activity, a major regional diesel user, adds its own demand swings on top of ordinary trucking.

PADD 4 is the only district that is genuinely small on both sides of the ledger. It has the least refining capacity and the least demand of the five, and the refineries it does have are clustered in a handful of places: the Salt Lake City area, Billings in Montana, and the Cheyenne and Denver corridor in Wyoming and Colorado. They run largely on regional crude, including waxy Uinta Basin barrels and Bakken production, which ties the district's input cost to local production rather than to a waterborne benchmark. What are PADDs explains how a district this small ended up reported alongside four much larger ones.

Isolation cuts both ways here. With little pipeline connection to neighboring districts, PADD 4 cannot easily import its way out of a local outage, so a single refinery going down moves the price more than the same event would anywhere else. It also means a global price shock reaches the Rockies later and softer than it reaches the coasts, because there is less arbitrage running through the district in either direction.

Demand has an industrial shape the trucking base does not explain. Oil and gas drilling is a major diesel consumer across Wyoming, Colorado, Utah and the Bakken side of Montana, and rig activity swings with the crude price, so a strong crude market raises this district's fuel demand at the same moment it raises the cost of making the fuel. Long hauls between scattered towns, high elevation and hard winters add the rest: cold-weather blending runs later into the spring here than in most of the country.

The Rocky Mountain vs. the US average page shows how that premium has tracked over time.