It is the purpose of this Bulletin to provide a general picture of the Rogue River and a more detailed river log of the wild reach of the river. The emphasis of the log is on the geology that the river canyon exposes. The wild reach of the Rogue River is sufficiently remote to have discouraged geologic reconnaissance in past years. Indeed, the same may be said of the Klamath Mountain Province in general. Recent interest in fitting the Klamath Mountains into the new global tectonic framework has brought about fresh interest in the geologic problems in this region, yet the difficulty of working in terrain as rugged and remote as this section of the Rogue River Canyon continues to discourage detailed geologic mapping. Consequently, the user of the River Log included in this Bulletin often will be told what kinds of rock he is seeing at a given point along the river, but may find that the origin of the rock is obscure or its age uncertain. Much more geologic work must be done in this region before these small pieces can be fitted together. The Bulletin attempts also to present the broad geographic and historical setting of the river along its course from the Cascade Mountains to the Pacific Ocean. This is done largely in preliminary sections preceding the River Log proper, though occasional biologic and historical notes punctuate the geologic observations that constitute most of the Log. It is hoped that hikers and boat travelers alike may come to understand the river better. Only in such understanding will its preservation lie.