If you are trying to figure out who will actually haul your freight, the Class I list is the shortest useful map of the industry there is. Six companies own the mainlines. Everything else — the six hundred-odd short lines, the terminal railroads, the switching operations — either feeds those six or works in the gaps between them. Knowing which Class I reaches your origin and which reaches your destination tells you more about your routing options and your pricing leverage than any other single fact about your lane.
How Many Class I Railroads Are There?
There are six Class I freight railroads operating in the United States: BNSF Railway, Union Pacific, CSX Transportation, Norfolk Southern, Canadian National, and Canadian Pacific Kansas City. That is the number you want if you are a shipper trying to identify who can move your freight.
You will see the number seven quoted, and occasionally eight, which causes a lot of confusion. Here is where the discrepancy comes from:
- Amtrak clears the revenue threshold and is technically a Class I railroad. It is a passenger carrier and hauls no commercial freight, so shipper-facing counts leave it out. Counts that include it say seven.
- Ferromex is a major Mexican carrier that some North American tallies include alongside the six. It is not a U.S. carrier and is not classified by the STB, so U.S. lists exclude it.
- Older references still say seven freight carriers. Canadian Pacific and Kansas City Southern merged into CPKC in April 2023, and a lot of published material has not caught up.
Two of the six — CN and CPKC — are Canadian-headquartered but operate substantial U.S. networks through U.S. subsidiaries that file with the STB as Class I carriers. They are as much a part of the American rail network as the four U.S.-owned carriers, and for a shipper the distinction has no practical meaning.
What Actually Makes a Railroad Class I
Annual operating revenue. That is the entire test. The Surface Transportation Board publishes a revenue threshold and indexes it for inflation every year, and any railroad reporting revenue above that line is a Class I. Nothing about track miles, locomotive count, geography, train frequency, or service quality enters into it.
The threshold has moved a lot. The STB reset the base in 2021, raising it from $250 million (in 1991 dollars) to $900 million (in 2019 dollars), and it has been restated upward every year since as the Board applies its inflation deflator. For the 2025 reporting year the figure was $1,094,774,354. The Board publishes a new number each June, so the exact dollars change annually while the structure stays put.
| Class | Annual operating revenue (inflation-indexed) | Approximate count in the U.S. |
|---|---|---|
| Class I | Above roughly $1.1 billion | 6 freight carriers |
| Class II (regional) | Between roughly $47 million and the Class I line | Around 20 |
| Class III (short line) | Below roughly $47 million | Roughly 600, including switching and terminal carriers |
The revenue-only definition produces some odd results worth knowing about. A railroad can operate 900 miles of heavy-duty mainline, run through trains, and still be classified as a regional carrier because its revenue does not clear the bar — Montana Rail Link operated exactly that way for decades. Conversely, the classification carries real regulatory weight: Class I carriers file detailed annual financial and cost reports with the STB, including the Uniform Rail Costing System data that underpins rate-reasonableness analysis. Those filings are why the industry has public cost data at all, and they exist only for Class I carriers.
If your interest is the tier below, our companion guide on what a short line railroad is covers Class III carriers in the same depth, and the short line vs Class I comparison puts the two side by side on service and pricing behavior.
The Six Class I Railroads, One by One
What follows is the practical version — footprint, commodity strengths, and what a shipper should know. Route mileage figures are approximate and shift slightly year to year as carriers sell branches and abandon segments.
BNSF Railway
Roughly 32,500 route miles across the western two-thirds of the country, the largest network of the six by mileage. BNSF is privately held under Berkshire Hathaway, which means it does not report quarterly to public shareholders and has historically been willing to spend on capacity when its peers were cutting. For bulk shippers it is the dominant coal and grain carrier in the West, with heavy Powder River Basin and northern-plains grain density, plus major agricultural and industrial-product volumes.
Union Pacific
Roughly 32,000 route miles, also western, overlapping BNSF across most of its territory. UP is the largest of the six by revenue in most years and reaches all major western gateways and Gulf ports. Strong in chemicals, petroleum products, grain, industrial products, and automotive. Where UP and BNSF both serve a facility, a shipper has genuine competitive leverage; where only one does, the lane is captive, and pricing reflects it.
CSX Transportation
Roughly 20,000 route miles across the eastern United States, reaching the Atlantic ports and much of the eastern industrial base. Heavy in coal, aggregates, chemicals, agricultural products, and automotive. CSX and Norfolk Southern divide the East the way UP and BNSF divide the West, and much of eastern rail competition comes down to whether your facility can reach both.
Norfolk Southern
Roughly 19,500 route miles, also eastern, with dense coverage of the eastern industrial corridor and access to the Atlantic and Gulf. Strong in metals and construction materials, chemicals, automotive, and coal. NS is the subject of a pending merger application discussed below, which makes it the carrier whose future footprint is least settled.
Canadian National
CN operates roughly 20,000 route miles and is the only carrier of the six that touches three coasts — Pacific, Atlantic, and the Gulf. Its U.S. network runs down the middle of the country from the Great Lakes to the Gulf, which makes it an option a lot of shippers overlook when they assume the map is simply "two western railroads and two eastern railroads." Strong in grain, forest products, chemicals, petroleum, and metals.
Canadian Pacific Kansas City
Formed in April 2023 when Canadian Pacific and Kansas City Southern combined, CPKC operates roughly 20,000 route miles and is the only single-line railroad connecting Canada, the United States, and Mexico. That is a genuinely new capability in North American freight: cross-border moves that previously required an interchange at the border can now stay on one carrier. If you move freight to or from Mexico, CPKC changed your options, and it is worth re-checking routing assumptions that were built before 2023. Strong in grain, fertilizer, chemicals, automotive, and cross-border traffic.
How the Count Fell From Over 100 to Six
There were more than 100 Class I railroads in the 1950s. The collapse to six is the single most important piece of context for understanding how rail pricing works today, and it happened in three phases.
- Regulated decline, through the 1970s. Rate regulation left railroads unable to price their way out of trouble while trucking took the high-value freight. Bankruptcies piled up, culminating in the Penn Central failure — at the time the largest corporate bankruptcy in U.S. history — and the federal creation of Conrail out of the wreckage of the northeastern carriers.
- Deregulation and shedding, 1980 onward. The Staggers Rail Act let railroads price commercially, sign confidential contracts, and abandon or sell unprofitable branches. They did all three aggressively. Thousands of miles of low-density branch line went to new independent operators, which is where most of today's short line industry came from.
- Merger to the endpoint, 1990s to 2023. The survivors combined into progressively larger systems: BN and Santa Fe into BNSF, UP absorbing Southern Pacific, CSX and NS splitting Conrail between them, CN and CP each expanding into the U.S., and finally CP and KCS forming CPKC in 2023.
The result is a network that is financially healthy and operationally efficient, and also one where a large share of rail-served facilities have exactly one railroad at the door. That is the structural fact behind captive-shipper pricing, behind the long-running fight over reciprocal switching versus direct rail service, and behind why two shippers moving identical commodities identical distances can see wildly different rates. Competition on rail is geographic before it is anything else.
What Class I Status Means for Your Freight
Class I carriers account for roughly two-thirds of U.S. freight rail route mileage and the overwhelming majority of industry revenue. Practically, that translates into four things a shipper feels directly.
They own the long haul. Rail's cost advantage over truck comes from moving heavy freight long distances, and the mainlines that make that possible are Class I property. A short line can originate your car, but a Class I is almost certainly moving it the distance that makes rail worth doing. Our breakdown of rail vs truck costs per ton-mile covers where that economic line falls.
They set the rate. On a through-rated move, the Class I publishes the rate covering the entire origin-to-destination trip and divides the revenue with the connecting carriers behind the scenes. You see one number. The short line's share is negotiated between railroads, not with you — which is why a short line that wants to help you sometimes cannot. How rail freight rates actually get built walks through tariffs, contracts, and where the leverage sits.
They dictate the network's rhythm. Class I operating philosophy determines train frequency, yard cadence, and how long cars sit. When a Class I restructures its operating plan, every shipper on its network feels it, including shippers who never speak to that railroad directly because they interface only with a short line.
Their boundaries define your interchanges. Any move that crosses from one carrier's territory to another's involves a handoff, and handoffs are where cars dwell, get misrouted, and lose time. A single-line move on one Class I is generally cleaner and easier to price than a multi-carrier route. Our railroad interchange guide covers what happens at those junctions and how to protect a shipment moving through one.
Working With a Class I: What to Expect
Class I railroads are excellent at moving large volumes of heavy freight over long distances at low cost per ton-mile. They are, as a rule, not built to hold the hand of a shipper moving eight cars a quarter. Both statements are true simultaneously and neither is a criticism — it is what a business optimized around scale looks like.
Set expectations accordingly:
- Volume gets attention. Commercial teams are organized around large, repeating traffic. A committed multi-year volume commitment gets a different conversation than a one-off inquiry, and pricing follows the same logic.
- Rates are contract-driven and confidential. Most Class I freight moves under private contract rather than public tariff, which means you cannot look up what anyone else is paying. Benchmarking requires either a partner with market visibility or your own historical data.
- Equipment supply is a real constraint. Railroad-supplied cars are allocated, and allocation favors large committed shippers. If your commodity requires specialized equipment, sort out the car supply question before you sort out the rate — our guide to rail car types covers what each commodity needs.
- The accessorial and demurrage tariffs are the Class I's own. They are published, they are enforced, and they are usually less forgiving than a short line's. Read them before your first car arrives, not after the first invoice.
- Service is a network outcome, not a promise. Class I carriers publish trip plans, but performance varies with network conditions across the whole system. Build planning assumptions around observed performance on your specific lane rather than the plan.
The most common mistake we see from shippers new to rail is assuming a Class I relationship works like a truckload relationship — call, get a rate, book a load. It does not. Rail is a capacity-planning business, and the shippers who do well with it are the ones who bring forecast volume and consistent loading behavior to the conversation.
The Pending UP–NS Merger
Union Pacific and Norfolk Southern announced in July 2025 that they had agreed to combine, which would create the first single-line transcontinental railroad in the United States — a network spanning more than 50,000 route miles across 43 states.
The transaction is under review at the Surface Transportation Board and is not approved. The Board rejected the applicants' first filing as incomplete in January 2026, accepted a revised application in May 2026 while holding the proceeding in abeyance pending supplemental information, and the applicants completed those submissions in late July 2026. The companies have publicly said they expect to close in mid-2027 if the Board approves. Major rail mergers face a high regulatory bar — the STB's current merger rules require applicants to demonstrate the transaction is in the public interest and enhances competition, which is a stricter standard than the one that governed the 1990s consolidations.
What a shipper should do about it right now: nothing dramatic. If approved, the count of Class I freight carriers drops from six to five, and single-line service would open on a lot of lanes that currently require an eastern-to-western interchange. If you have lanes that cross the Mississippi corridor today, it is worth knowing which of your interchanges the combination would eliminate — but building a plan around an unapproved merger with a 2027 target date is not a good use of your time. Watch it; do not bet on it.
Whatever the outcome, the underlying question for any shipper stays the same: which carriers actually reach your origin and your destination, what does the all-in cost of each routing look like, and where do you have leverage. That analysis is lane-by-lane work, and it is exactly what a rail logistics provider does. If you would rather build the capability in-house, our free rail logistics course covers carrier structure, network design, and pricing across ten modules, and the rail freight glossary is worth bookmarking for the terminology that comes up in carrier conversations.
Frequently Asked Questions
How many Class 1 railroads are there?
There are six Class I freight railroads operating in the United States: BNSF Railway, Union Pacific, CSX Transportation, Norfolk Southern, Canadian National, and Canadian Pacific Kansas City. Some counts say seven because Amtrak clears the revenue threshold and is technically classified as a Class I, but it is a passenger carrier and moves no freight for shippers. If you are asking as a shipper, the working answer is six.
What makes a railroad a Class 1 railroad?
Annual operating revenue, and nothing else. The Surface Transportation Board sets a revenue threshold and indexes it for inflation every year. A railroad above the threshold is Class I; below it, the carrier is Class II or Class III. The threshold has been restated upward each year and now sits near $1.1 billion. Track miles, train counts, and geography have no bearing on the classification.
Which is the largest Class I railroad?
By route miles and by revenue, BNSF Railway and Union Pacific are the two largest, each operating roughly 32,000 route miles across the western two-thirds of the country. The two are close enough that the ranking shifts depending on whether you measure by revenue, route miles, carloads, or ton-miles. For a shipper the ranking is largely irrelevant, since which carrier serves your facility is a matter of geography, not size.
Can I ship directly with a Class I railroad?
Yes, if you have the volume and the rail access. Class I railroads sell directly to shippers and will quote a lane, but their commercial teams are built around large, repeating volumes. A shipper moving a few cars a month often gets little attention going direct, which is why many work through a rail logistics provider or route their freight through a short line or transload facility that already has a relationship with the Class I.
What is the difference between a Class 1 and a Class 3 railroad?
Revenue scale, and everything that follows from it. Class I railroads earn above the STB threshold of roughly $1.1 billion a year and run continental long-haul networks. Class III railroads, commonly called short lines, earn under roughly $47 million and typically operate a single branch or small cluster of branches connecting local industries to the larger network. A single move frequently uses both: a short line handles the first or last miles, and a Class I handles the long haul.