3 ft gauge railroads in the United States

A list of 3 ft (914 mm) narrow gauge railways in the United States.

Narrow gauge railroads of various sizes existed across the US, especially during the late 1800s, with the most popular gauge being 3 ft gauge. Some of the more famous 3 ft gauge railroad networks in the US were based in California, Colorado, and Hawaii. These narrow gauge lines were easier to build than standard gauge, and cost significantly less to construct. Some of the lines of these former networks still exist in the present day and continue to use 3 ft gauge track; the rest were either widened to standard gauge or abandoned (see table below).