Developed as part of an international curriculum effort, this unit aims to provide information to students about the interdependence of Pacific nations and the importance of the Columbia River and its ports in international trade. Geared for grades 5-7, the materials focus on harbors both as natural ecosystems and as locations of international ports for the exchange of raw materials and manufactured goods. Part 1 of the guide includes lessons which present activities related to: (1) entering the harbor; (2) use of the harbor; (3) the harbor environment; and (4) you and your harbor. A series of readings comprise part 2. Part 3 contains vocabulary lists which are designed to be used with the specific readings found in section 2. (ML)