Warning: virtual(): Headers already sent. You cannot change the session module's ini settings at this time in /wc/blm/ext/doc/or/resources/recreation/csnm/csnm-history.php on line 2

Warning: virtual(): Headers already sent. You cannot change the session module's ini settings at this time in /wc/blm/ext/doc/or/includes/global/template/template.php on line 102

Warning: Use of undefined constant GLOBAL_TRACKING_GOOGLE - assumed 'GLOBAL_TRACKING_GOOGLE' (this will throw an Error in a future version of PHP) in /wc/blm/ext/doc/or/includes/global/template/tracking.php on line 1

Warning: virtual(): Headers already sent. You cannot change the session module's ini settings at this time in /wc/blm/ext/doc/or/resources/recreation/csnm/csnm-history.php on line 3
Natural History Oregon/Washington BLM



Natural History


Flint Rocks
Photo courtesy of Paul Hosten

The remnant of an ancient volcano, Pilot Rock stands out as one of the most striking features of the Cascade-Siskiyou National Monument. Below Pilot Rock lies a landscape brimming with ecological diversity and wonder; a landscape where a short hike leads the explorer from a warm, wildflower and boulder strewn meadow, into the quiet grandeur of a cool, moss-covered forest where animals seek shelter from the heat of the day. An opening in the forest lets hikers look out across the rocky ridges of the Siskiyous, the wide expanse of the Shasta Valley, and the towering snow-capped volcanic peak of Mount Shasta, while hundreds of colorful butterflies search for nectar in the plants at their feet. It is the butterflies and plants, as well as the mountains, volcanoes and valleys that help decipher the ecological story of the area.


Geological and climatological influences from the north, south, west and east meet at the convergence of southwestern Oregon's Cascade, Siskiyou and Klamath mountain ranges. Plants and animals typically found in ecologically distinct regions, come together in an array of species richness and diversity unmatched anywhere in the Cascade Mountains. The Cascade-Siskiyou National Monument represents the heart of this fascinating region.

The ecologically distinct regions represented by species in the Cascade-Siskiyou National Monument are known as ecoregions. Ecologists classify areas as ecoregions based upon unique combinations of topography, geology, soils, climate, and vegetation. In this case, multiple ecoregions meet, making for an ecologically jumbled landscape. Plant communities, for example, represent a mixing of the vegetation types found in the Great Basin, Cascades and Klamath Mountains. Other species typically found east of the Cascades, such as pygmy nut hatches and kangaroo rats, share habitat with western species such as rough-skinned newts and northern spotted owls. The Jenny Creek portion of the monument is a significant center of fresh water snail diversity, and is home to three endemic fish species. Throughout the Monument, a highly unusual assemblage of butterflies representative of ecoregions that lie to the north, south, west and east, fly next to one another.


The Monument's ecological richness is influenced in large part by the region's extremely complex geology. A majority of the Monument lies within the relatively young, volcanic Cascade Range. The southwestern portion of the Monument is in the much older Siskiyou Mountains. The Siskiyou Mountains, considered a part of the Klamath Mountains, contain the oldest known rocks in Oregon at 425 million years old. The differences in rock types and ages provide the foundation for a variety of soil types and habitats.

Another important factor in the geologic makeup of the area, is the east-west orientation of the Siskiyou Mountains. An unusual orientation for a large mountain range, the Siskiyous provide plant and animal species with a critical connection between the Cascades and the wet forests of the western coastal ranges. In addition, the Klamath Mountains were not glaciated in the last ice age and served as a refuge for species whose former habitat disappeared under tons of continental ice. The final ingredients in the recipe for diversity, are the sudden changes in elevation and aspect that affect sun exposure, moisture, and temperature throughout the Monument.

Cultural History

Flint Rocks
Photo courtesy of Frank Lang

This geologically and ecologically diverse region has provided a home for native peoples for thousands of years. Numerous archaeological and historical sites, including areas of traditional cultural importance such as spiritual sites and root gathering areas are found throughout the Monument. Archaeological surveys in the Cascade-Siskiyou National Monument have located close to one hundred sites relating from the native peoples' use of the area. These are typically areas where open meadows, oaks, and game, including deer and elk, still exist. The Monument also contains remnants of the National Historic Applegate and Oregon/California Trails. Rock alignments, blazed trees, and artifacts such as cast off ox shoes document these historic routes.


Field Trip
Photo courtesy of Lorie List

Beyond the scientific and historic significance of the area, the Cascade-Siskiyou National Monument provides visitors with great recreational and educational opportunities. At Hyatt Lake, located at the Monument's northern boundary, families enjoy camping, fishing, and hiking. Hikers, backpackers, and horse users can explore the core of the monument on the Pacific Crest National Scenic Trail. The area invites exploration and discovery. Visitors should be aware and respectful of the large tracts of private property interspersed with Monument lands.