Pacific Lamprey (Entosphenus tridentatus) are among the oldest fish species in the world, appearing in the fossil record about 450 million years ago. They have elongated bodies (eel-like), with no scales or bones. Their most characteristic feature is a large, jawless suction-cup style mouth that they use to attached to rocks to rest between bursts of swimming or to climb waterfalls. Lamprey use their sucking disk to attach to fish and marine mammals in the ocean to feed on blood and fluids. They begin life in freshwater streams in the Pacific Northwest (to Baja Mexico) and around the Pacific Rim where they live for 3-7 years before they migrate to the ocean. As adults they return to freshwater streams to spawn much like salmon. Although they have survived three ice ages and five mass extinction events, their populations have declined in recent decades and their range has been constricted. The Native American Tribes of the Pacific Northwest, especially the tribes along the Columbia River, have harvested lamprey for thousands of years and prize them for cultural, spiritual, and ceremonial uses. This talk will present a summary of research that supports efforts to protect and restore these ancient fish.