List of auto trails in Maine

Auto trails in Maine
Maine's early highway system
System information
Maintained by MaineDOT
Highway names
Interstates	Interstate x (abbreviated I-X)
US Highways	U.S. Route x (abbreviated US-X)
State	State Route x or Route x (abbreviated SR X)
Lettered routes	Route x
System links
Maine State Highway System Interstate US State Auto trails Lettered highways

Maine was one of the first states to mark their state highway system. From 1914 to 1925, Maine used a system of lettered highways to designate cross-state routes. This system was the first of its kind in the United States coordinated by a single state,^{[citation needed]} predating Wisconsin's system by three years.^{[citation needed]} In 1919, this system was supplanted by a series of auto trails officially created by the State Highway Commission, though it is unclear as to whether this system completely supplanted the lettering system. Both systems were abandoned by 1925 in favor of the New England interstate highway system.^{[citation needed]}