| State/territory |
Railway |
| Alabama |
|
| Alaska |
- Alaska Railroad (standard gauge lines also present) (dual gauge lines with standard gauge track previously present) (defunct - standard gauge lines still operating)
- Crooked Creek & Whiskey Island Railroad (located in Pioneer Park) (operating)
|
| Arizona |
- Legend City Railroad (located in Legend City) (defunct)
|
| Arkansas |
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| California |
- California State Railroad Museum (standard gauge lines and dual gauge lines with standard gauge track also present) (all 3 ft gauge trackage is dual-gauged with standard gauge trackage) (operating)
- Neverland Valley Railroad (located in Neverland Ranch, the late Michael Jackson's home and amusement park) (separate 2 ft (610 mm) gauge railway also present) (defunct)
- Northwestern Pacific Railroad (standard gauge lines also present) (dual gauge lines with standard gauge track previously present) (defunct - standard gauge lines still operating)
|
| Colorado |
- Gilpin Railroad (2 ft (610 mm) gauge lines and dual gauge lines with 2 ft gauge track also present) (all 3 ft (914 mm) gauge trackage was dual-gauged with 2 ft gauge trackage) (defunct)
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| Connecticut |
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| Florida |
- Pioneer & Western Railroad (located in Pioneer City) (defunct)
|
| Georgia |
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| Hawaii |
|
| Idaho |
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| Illinois |
|
| Indiana |
- Hesston Steam Museum (2 ft (610 mm) gauge lines and dual gauge lines with 2 ft gauge track also present) (all 3 ft (914 mm) gauge trackage is dual-gauged with 2 ft gauge trackage) (separate 14 in (356 mm) gauge railway and separate 7 1⁄2 in (190.5 mm) gauge railway also present) (operating)
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| Iowa |
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| Kentucky |
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| Louisiana |
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| Maryland |
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| Massachusetts |
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| Michigan |
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| Mississippi |
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| Missouri |
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| Montana |
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| Nebraska |
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| Nevada |
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| New Jersey |
|
| New Mexico |
|
| New York |
|
| North Carolina |
- Carowinds and Carolina Railroad (crossed into South Carolina) (located in Carowinds) (defunct - park still operating)
|
| Ohio |
- Bellaire and St. Clairsville Narrow Gauge Railway[6] (defunct)
- Iron Railroad (4 ft 10 in (1,473 mm) Ohio gauge lines and dual gauge lines with 4 ft 10 in track also present) (all 3 ft (914 mm) gauge trackage was dual-gauged with 4 ft 10 in trackage) (defunct)
- St. Clairsville Railway[6] (defunct)
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| Oklahoma |
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| Oregon |
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| Pennsylvania |
- Daniel Tiger's Neighborhood Trolley Ride (located in Idlewild and Soak Zone) (separate 2 ft (610 mm) gauge railway named Loyalhanna Limited Railroad also present) (operating)
- Little Saw Mill Run Railroad (dual gauge lines with standard gauge track previously present) (all 3 ft (914 mm) gauge trackage was dual-gauged with standard gauge trackage) (defunct)
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| Puerto Rico |
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| South Carolina |
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| South Dakota |
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| Tennessee |
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| Texas |
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| Utah |
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| Vermont |
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| Virginia |
- Old Dominion Line (located in Kings Dominion) (defunct - park still operating)
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| Washington |
- Cascades Railroad (converted from 5 ft (1,524 mm) gauge, then converted from standard gauge) (defunct)
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| West Virginia |
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| Wisconsin |
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| Wyoming |
- Oregon Short Line Railway (crossed into Idaho and Oregon) (dual gauge lines with standard gauge track previously present) (all 3 ft (914 mm) gauge trackage was dual-gauged with standard gauge trackage) (defunct)
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