Fresh water is a valuable and essential commodity in the Pacific Northwest States, specifically Oregon, Washington, and Idaho, and one provided abundantly by forested watersheds in the region. The maintenance and growth of industrial, municipal, agricultural, and recreational activities in the region are dependent on adequate and sustainable supplies of fresh water from surface and ground-water sources. Future development, especially in the semiarid intermountain area, depends on the conservation and expansion of the region's water resource. This synthesis reviews the state of our knowledge and condition of water resources in the Pacific Northwest.