Cache La Poudre River Basin Heritage Study Act - Directs the Secretary of the Interior to prepare a study of alternatives for the Cache La Poudre River Basin in Colorado, including: (1) an inventory and assessment of significant cultural, natural, recreational, and scenic resources throughout the Basin; (2) an evaluation of properties to determine potential eligibility for inclusion on the National Register of Historic Places; (3) the suitability and feasibility of designating the Basin as a National Heritage Area; and (4) the identification of preservation strategies for resources located within the Basin, and management alternatives and funding options for the implementation of such strategies. Authorizes the Secretary to undertake a demonstration project to evaluate the potential of using voluntary land exchanges within the Cache La Poudre River flood plain as a means to provide for the long-term preservation and management of the lands within the floodplain. Establishes the Cock La Poudre River Basin Heritage Advisory Commission to advise the Secretary on the preparation of the study. Authorizes appropriations.