Certain features unique to the Pacific Northwest influence landsliding in this region. Weakly consolidated sediments, dense vegetation and seasonally concentrated rainfall all contribute to the distinctive conditions that are encountered here. This study gathers together information applying to the recognition and correction of Pacific Northwest landslides. Treatment practices common to this region are discussed. A large slide located about 30 miles east of Portland, Oregon along the Clackamas River is used as an example. Exploration, instrumentation, analysis and corrective measures are illustrated.