Oil refineries in the United States are concentrated along the Gulf Coast of Texas and Louisiana, with smaller clusters in California, the Midwest, and the Rocky Mountain states. As of January 2025, the country’s total operable refining capacity stands at 18.4 million barrels per calendar day, spread across five broad geographic zones the federal government calls Petroleum Administration for Defense Districts, or PADDs.
The Gulf Coast: America’s Refining Capital
PADD 3, covering Texas, Louisiana, Mississippi, Alabama, Arkansas, and New Mexico, is home to the densest concentration of refining infrastructure in the country. The Texas Gulf Coast alone hosts the three largest individual refineries in the United States. Marathon Petroleum’s Galveston Bay facility leads at 631,000 barrels per calendar day, followed by Motiva Enterprises’ Port Arthur refinery at 626,000 barrels and ExxonMobil’s Beaumont refinery at 609,024 barrels. All three sit within a roughly 100-mile stretch of the southeastern Texas coastline.
Louisiana’s Gulf Coast adds another major layer. Refineries there benefit from the same geographic advantages that made Texas dominant: deepwater ports for importing crude, pipeline networks connecting to inland oil fields, and the Mississippi River corridor for distributing finished products. Northern Louisiana and Arkansas host smaller facilities as well. The Gulf Coast region’s dominance comes down to decades of infrastructure investment, proximity to offshore drilling in the Gulf of Mexico, and flat coastal land suitable for the enormous footprint these facilities require.
California and the West Coast
California operates its own largely self-contained refining system, with a combined capacity of about 1.48 million barrels per day across 12 facilities. The state’s refineries cluster in two main areas: the Los Angeles basin and the San Francisco Bay Area.
In Southern California, Marathon Petroleum’s Los Angeles Refinery is the largest at 365,000 barrels per day, accounting for nearly a quarter of the state’s total capacity. Chevron’s El Segundo facility (269,000 barrels per day) and PBF Energy’s Torrance refinery (160,000 barrels per day) round out the major players in the region. The cities of Wilmington, South Gate, and El Segundo all sit within roughly 20 miles of each other, forming a tight refining corridor near the Port of Los Angeles.
In Northern California, refineries line the eastern shore of San Francisco Bay. Chevron’s Richmond refinery processes 245,271 barrels per day, while PBF’s Martinez facility handles 156,400 and Valero’s Benicia refinery runs at 145,000. That Benicia plant is scheduled to cease refining operations by the end of April 2026, which will meaningfully reduce the Bay Area’s output. A couple of smaller refineries in Bakersfield, in the Central Valley, process crude from nearby oil fields but contribute only a small fraction of the state’s total.
Washington and Alaska also fall within this western zone, though their refining capacity is far smaller than California’s.
Midwest Refining Hubs
PADD 2 covers 15 states stretching from the Dakotas down through Oklahoma and east to Ohio. The heaviest refining activity sits in Illinois, Indiana, and Kentucky, where facilities process crude arriving by pipeline from Canada’s oil sands and from domestic production in North Dakota and Oklahoma. Other Midwest states with refining operations include Minnesota, Kansas, Ohio, and Michigan, though at a smaller scale. These refineries primarily serve regional demand for gasoline, diesel, and jet fuel rather than exporting products the way Gulf Coast plants do.
Rocky Mountain and East Coast Facilities
The Rocky Mountain region, PADD 4, includes Colorado, Montana, Wyoming, Utah, and Idaho. Refineries here tend to be smaller and serve local and regional markets. Wyoming and Montana process crude from nearby fields, while Utah refineries handle oil from the Uinta Basin. Geographic isolation from coastal shipping infrastructure means these plants operate somewhat independently from national supply chains.
The East Coast, PADD 1, has the fewest refineries relative to its population. Most of the region’s refining capacity was historically based in the Philadelphia area of Pennsylvania and in New Jersey. Several East Coast refineries have closed over the past decade, leaving the region heavily dependent on fuel shipped up from the Gulf Coast or imported from abroad. The Central Atlantic subdistrict (Delaware, New Jersey, New York, Pennsylvania, Maryland) retains some capacity, but New England and the Southeast have virtually none.
Why Refineries Are Where They Are
Refinery locations reflect a few basic economic realities. Access to crude oil supply is the most obvious: Gulf Coast refineries sit near offshore production and receive pipeline deliveries from across the country. Access to water matters too, both for the massive volumes of cooling water refineries consume and for shipping finished products by barge and tanker. Deep ports along the Texas and Louisiana coasts make it economical to both import crude and export refined fuels.
Historical momentum plays a large role as well. No new large-scale refinery has been built in the United States in decades. Existing facilities expand incrementally instead, adding processing units to boost capacity. That means today’s refinery map largely reflects decisions made 50 to 100 years ago, when proximity to oil fields and shipping routes locked in locations that still make logistical sense.
Shifting Capacity
Total U.S. refining capacity has remained largely unchanged heading into 2025, but the mix is shifting. Two pending refinery closures are expected to reduce domestic production of refined petroleum products in the near term. Some former petroleum refineries have converted to producing renewable diesel, a trend that has pushed renewable fuels from about 5% of U.S. distillate consumption in 2021 to a forecasted 9% in the coming year. California has seen the most conversion activity, consistent with the state’s aggressive clean fuel mandates. These conversions don’t always mean a facility disappears from the map, but the product coming out the other end changes significantly.