National Heritage Area Act of 2017 This bill establishes a National Heritage Areas System to recognize certain areas of the United States that tell nationally significant stories and to conserve, enhance, and interpret the areas' natural, historic, scenic, and cultural resources that illustrate significant aspects of U.S. heritage. Through such system, the Department of the Interior may provide technical and financial assistance to local coordinating entities to support the establishment, development, and continuity of such areas. The system shall be comprised of: such areas designated by Congress under this bill; such areas designated after enactment of this bill, unless the law designating the area exempts it from inclusion in the system; and 49 specified areas; and any other national heritage areas designated before this bill's enactment. National heritage areas shall not be considered to be units of the National Park System. Interior shall: (1) undertake studies as directed by Congress to assess the feasibility of designating proposed national heritage areas, (2) approve or disapprove the management plan prepared by the local coordinating entity for an area, and (3) evaluate the accomplishments of an area every 10 years after its designation and submit a recommendation on whether federal funding for such area should be continued, reduced, or eliminated. The bill: (1) specifies the criteria that Interior shall apply to determine the suitability and feasibility of designating proposed national heritage areas, and (2) states that the designation of an area shall be by federal statute and contingent on the prior completion of a management plan and an affirmative determination by Interior that the area meets such criteria.