Photo by: David Mark

The Klamath River Basin covers an enormous area and consists of diverse landscapes including marshlands, lava fields, semi-arid grasslands, dense forests, and steep wooded mountains. This wide reaching and complex series of ecosystems has been shaped by geological events that many are either unaware of or have little knowledge of. The Basin would not be as it is today without a long history of volcanic activity that generated mountains and pumped lava flows to create the landscapes that the Klamath River flows from and through. Crater Lake in Southern Oregon and Mount Shasta in Northern California are products of these volcanic processes that have shaped the hydrogeological realities of the Basin.

The oral history of the Klamath Tribe contains a story that describes the eruption of Mount Mazama in spiritual terms. According to the Klamath worldview, the creation of Crater Lake was the outcome of a battle between spirits competing for control of a portal to the “Below World.” This way of explaining volcanism without a scientific framework illustrates one way that people who have called the Klamath River Basin home since time immemorial have come to understand their territories’ propensity for dramatic geological transformation.

Mount Shasta is another important volcano in the hydrogeological systems of the Klamath River Basin. Visitors and residents alike may recognize the ice-topped peak that reaches just shy of 10,000 feet and can be seen from California’s Central Valley. Mount Shasta, due to its volcanic origins, is particularly porous. This porosity leads to much of the rainwater that falls on the mountain rapidly entering ground water networks that feed the headwaters of the Klamath River. The steep angles of the mountain have been less eroded by rainfall and snowmelt as they would be if it made up of less-porous stone.

Volcanoes may not be the first image that people conjure in their minds when thinking about the Klamath River Basin, but the region is intrinsically linked to volcanic activity. The Volcanic Legacy Scenic Byway provides a unique opportunity for those interested in visiting the volcanoes that have shaped the Basin. Investigating the geological history of the Klamath River Basin offers visitors and residents alike an opportunity to better understand how these places became what they are today furthering an appreciation of the region’s diverse and spectacular landscapes.