In 1966, in response to a growing interest in historic preservation and after a series of well-publicized building demolitions, the National Historic Preservation Act was passed by Congress. Among its many notable accomplishments was the creation of the National Register of Historic Places, the requirement for each state to have a State Historic Preservation Officer or SHPO (popularly referred to as the “ship-o”), and a legal review process, Section 106 of the Act, to monitor the impact of federal actions on recognized historic properties.

The National Register of Historic Places, maintained by the National Park Service, serves as the nation’s principal acknowledgement and recognition of historic buildings, structures, objects, sites and districts. To be listed in the National Register, a nomination form must be prepared and submitted to the State Historic Preservation Officer, be fifty years old or older (there may be exceptions for outstanding resources less than fifty years old) and meet criteria and integrity requirements established by the US Secretary of the Interior. While listing in the National Register is the accepted threshold establishing credibility for historic resources, it does not, per se, provide any protection for listed properties. In fact, scores of National Register properties are lost to demolition each year.

Protection of listed properties, not a federal requirement, is provided by many state and local governments. These laws and policies vary tremendously by jurisdiction, with the most rigorous generally found at the local government level. The federal government is required, through Section 106 of the National Historic Preservation Act of 1966, “to take into account” the effects of federally funded or sponsored projects (or private projects that are subject to federal licensing, permitting or approval) on historic sites that are listed in or “determined eligible” for listing in the National Register of Historic Places. “Determination of Eligibility” (DOE) is made by the SHPO based on evidence of the historic qualities of a property without undertaking a full nomination process—DOE’s are generally undertaken for projects that involve federal funding.

For historic roads, listing in the National Register, or a DOE, requires the managing agency (local, state or federal) to undertake a review of the proposed action and determine its effects on the integrity of the historic road if federal funds (in whole or in part) are being used. Often this leads to a modification of the proposed action to protect the historic resource. In instances the historic property can be altered, even destroyed, if there is a compelling reason for the action. Under such circumstances mitigation for the loss must be arranged in an agreement with the managing agency (often the DOT) and the SHPO.