The Biggest Oil and Gas Pipelines in the United States

Few industries symbolize America’s industrial scale and infrastructure prowess like its oil and gas pipeline network. Spanning more than 3 million miles, the U.S. energy pipeline system is the world’s largest, a vast, interconnected web that powers the economy, fuels transportation, and supports global energy markets.

The U.S. pipeline boom took shape in the early 20th century, following the rise of Standard Oil and the expansion of Gulf Coast refineries. Over decades, thousands of miles of steel were laid across deserts, plains, and mountains, moving crude oil, refined fuels, and natural gas from resource basins to refineries, cities, and export terminals.

Today, these systems represent hundreds of billions of dollars in cumulative investment and ongoing modernization. Major operators like Enbridge, Kinder Morgan, Plains All American, and Williams Companies continue to expand, upgrade, or reverse pipeline flows to meet shifting energy patterns. The rise of U.S. shale, particularly from the Permian Basin, Bakken, and Marcellus, transformed infrastructure needs, prompting new construction and expansions toward Gulf Coast export hubs.

Below, we examine the largest and most important crude oil, refined product, and natural gas pipelines in the United States, along with key facts on their size, capacity, and strategic roles.

Major Crude Oil Pipelines

PipelineApprox. Length (mi)Capacity (bpd)Route / Key DetailsOwner / Operator
Colonial Pipeline5,5002.5 millionFrom Houston, TX to Linden, NJ — transports refined products but also handles crude blendstocksColonial Pipeline Co. (Koch, Shell, others)
Keystone Pipeline (U.S. Section)2,687 (full system)830,000Alberta to Cushing, OK and the Gulf CoastTC Energy
Enbridge Mainline System3,000+ (U.S. portion)2.9 millionMoves Canadian crude from the border to U.S. refineriesEnbridge Inc.
Plains All American Pipeline System18,000+ (network)1–2 million (varies)Multiple routes connecting Permian, Bakken, and Cushing to Gulf CoastPlains All American
Magellan Crude Oil Pipeline System2,200600,000Moves crude from the Permian Basin and Midcontinent to Gulf refineriesMagellan Midstream (Oneok)
Seaway Pipeline850850,000From Cushing, OK to Freeport, TX (Gulf Coast)Enbridge & Enterprise Products Partners
Capline632300,000 (reversed flow)Alberta to Cushing, OK, and the Gulf CoastPlains, Marathon, BP

These crude oil systems are the arteries of U.S. petroleum logistics. The Enbridge Mainline and Keystone networks move vast volumes of Canadian crude into American refineries, while systems like Seaway and Magellan link domestic basins to Gulf Coast refining and export hubs.

Refined Product Pipelines

PipelineApprox. Length (mi)Capacity (bpd)Route / Key DetailsOwner / Operator
Colonial Pipeline5,5002.5 millionPrimary fuel artery from Gulf Coast refineries to East Coast marketsColonial Pipeline Co.
Explorer Pipeline1,830660,000Houston to ChicagoExplorer Pipeline Co.
Magellan Products System9,800700,000Midwest to Gulf Coast, distributing gasoline, diesel, jet fuelMagellan Midstream (Oneok)
Plantation Pipeline3,100700,000Baton Rouge, LA to Washington, D.C.Kinder Morgan & ExxonMobil

The Colonial Pipeline is particularly vital; it supplies nearly 45% of the East Coast’s gasoline, diesel, and jet fuel. A single disruption, as seen during the 2021 cyberattack, can ripple through markets nationwide. The Magellan and Explorer systems play complementary roles, moving refined products between the Midwest, Gulf Coast, and major consumption hubs.

Major Natural Gas Pipelines

PipelineApprox. Length (mi)Capacity (bcf/day)Route / Key DetailsOwner / Operator
Texas Eastern Transmission (TETCO)9,10011.0Gulf Coast to Northeast U.S.Enbridge
Transcontinental Gas Pipe Line (Transco)10,20015.0Texas to New York City — backbone of East Coast gas deliveryWilliams Companies
Northern Natural Gas14,7005.5Permian and Midcontinent to MidwestBerkshire Hathaway Energy
Tennessee Gas Pipeline11,9008.0Gulf Coast to NortheastKinder Morgan
El Paso Natural Gas (EPNG)10,0005.7Southwest (Permian, San Juan) to California and ArizonaKinder Morgan
ANR Pipeline9,4006.5Gulf Coast to Midwest and Great LakesTC Energy
Rockies Express Pipeline (REX)1,7125.8West-to-East trunkline from Rockies to OhioTallgrass Energy
Alliance Pipeline2,3001.6Western Canada to Chicago areaEnbridge & Pembina

The Transco system, owned by Williams, is the largest natural gas pipeline in the United States by throughput, delivering up to 15 billion cubic feet per day from Texas to the New York metro area. These pipelines form the invisible backbone of America’s electricity generation and heating infrastructure, feeding power plants, industrial users, and residential consumers alike.

Fast Facts

  • Transco is the largest natural gas pipeline system in the U.S. by daily volume.
  • Colonial is the most critical refined products artery, supplying nearly half of the East Coast’s fuel.
  • Enbridge’s Mainline System is the largest cross-border crude oil network linking Canada and the U.S.
  • Seaway and Keystone serve as key conduits connecting Permian and Canadian crude to Gulf Coast refineries and export terminals.

Conclusion

The U.S. pipeline network is one of the most important and understated pieces of national infrastructure. These massive, underground systems enable energy independence, stabilize fuel prices, and support manufacturing, logistics, and power generation across North America.

While the global transition toward low-carbon energy continues, pipelines remain central to meeting today’s demand and tomorrow’s transition. Upgrades are increasingly focused on reducing methane leaks, improving digital monitoring, and preparing rights-of-way for future hydrogen blending or carbon capture transport.

For decades, the U.S. has quietly led the world in energy logistics, a position secured not only by its production scale but by the engineering, capital, and planning that built and continues to evolve this vast energy network.

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