Any work carried out to achieve historic preservation goals is called "treatment" in Secretary of the Interior guidance documents, and the term is used here in that broad sense. Treatment may refer to ongoing management of historic properties, or it can be activities conducted as mitigation of a projectís adverse effects, such as in an archeological treatment plan.

While treatment can encompass various activities, decisions on the specific treatment of historic landscapes should be based on the Secretary of the Interiorís Standards for the Treatment of Historic Properties and the recommended procedures in Guidelines for the Treatment of Historic Landscapes. These Standards and Guidelines base treatment on an understanding of historic propertiesí significance and integrity.

Every effort should be made to retain a landscapeís key characteristics; to repair damaged features with in-kind materials; to be authentic and avoid speculative reconstructions; to respect past changes which may have acquired their own significance; and to avoid destroying historic materials. In some instances, more than one treatment method may apply. Refer to the Guidelines for the Treatment of Historic Landscapes for specific treatment situations.