Geology Focused  River Trips

Explore the Varied & Dynamic Geology of the Northwest

Owyhee River

5 days - rome to birch creek

April 9 - 13, 2024

Geology  Focused with Dr. Gordon Grant

$1,879.00 (Adult)

Minimum age for this trip is 12

The geology of the Owyhee River Canyon is a wonderfully complex cornucopia of cataclysm. The river's steep-walled canyons and valleys record 5 million years of geologic drama and intrigue. The small but mighty Owyhee has faced epic and repeated struggles against lava flows, landslides while conveying catastrophic outburst floods from the lakes they create. It has also conveyed at least one immense flood from catastrophic overflow from a huge late Pleistocene lake beyond its watershed.

Lava has repeatedly entered the Owyhee Canyon and filled it creating wedge-shaped dams of solid basalt. The Owyhee takes 10,000s of years to cut through the lava dams and pass the sediment once held in their lakes.  In addition, landslides collapse from canyon walls  dumping immense loads of bouldery debris directly into the river's path. They are no match to lava dams and their lakes quickly  breach creating catastrophic floods leaving impressive boulder bars and erosional scars in their wake.

Stretches of steep canyon walls composed of thick layers of massive basalt and rhyolite alternate with stretches carved through dramatic and colorful badlands composed of lake sediments, thin lava flows, dikes, sills, and volcanic ash. The entire landscape is a testament to the sheer persistence of the river.

Owyhee River

5 Days - rome to birch creek

April 16 - 20, 2024

Geology  Focused with Dr. Kyle House

$1,879.00 (Adult)   

Minimum age for this trip is 12

The geology of the Owyhee River Canyon is a wonderfully complex cornucopia of cataclysm. The river's steep-walled canyons and valleys record 5 million years of geologic drama and intrigue. The small but mighty Owyhee has faced epic and repeated struggles against lava flows, landslides while conveying catastrophic outburst floods from the lakes they create. It has also conveyed at least one immense flood from catastrophic overflow from a huge late Pleistocene lake beyond its watershed.

Lava has repeatedly entered the Owyhee Canyon and filled it creating wedge-shaped dams of solid basalt. The Owyhee takes 10,000s of years to cut through the lava dams and pass the sediment once held in their lakes.  In addition, landslides collapse from canyon walls  dumping immense loads of bouldery debris directly into the river's path. They are no match to lava dams and their lakes quickly  breach creating catastrophic floods leaving impressive boulder bars and erosional scars in their wake.

Stretches of steep canyon walls composed of thick layers of massive basalt and rhyolite alternate with stretches carved through dramatic and colorful badlands composed of lake sediments, thin lava flows, dikes, sills, and volcanic ash. The entire landscape is a testament to the sheer persistence of the river.

John Day River

4 days - service creek to clarno

June 3-6, 2024

Geology  Focused with Dr. Emily Cahoon

$1,259.00 (Adult)

$1,209.00 (Youth - 6 to 12)

The John Day River basin includes a variety of geologic phenomena, from scraps of ancient islands and coral reefs to remnants of 45-million-year-old volcanoes and the southern-most exposures of vast lava flows that covered the Columbia basin.

The colorful story of Oregon’s geologic history is evident in the rugged landscape of the Clarno Volcanics, the colorful, ash-laden volcanic layers of the John Day Formation and the dark basalt flows that cap most of the landscape.

The section of the river corridor between Service Creek and Clarno best features the Clarno Formation rocks which are the remnants of Eocene volcanoes. The climate of the Eocene was sub-tropical, with heavy rainfall each year.  Clarno volcanic rocks are similar to those of the modern Cascades with the most common rock types being  andesites, lahars or volcanic debris flows, basalts and dacites.

Deschutes River

3 Days - TROUT CREEK TO MAUPIN

July 23-25, 2024

Railroad History & Geology Focused Trip with

William Burgel

$995.00 (Adult)   

$945.00 (Youth - 7 to 12)

Geology - Geology on the Lower Deschutes River is characterized primarily by Columbia River Basalt Flows. Occurring 14 million to 17 million years ago these massive eruptions covered significant portions of eastern Oregon and Washington with layer upon layer of lava. The Deschutes River maintained its northward course to the Columbia River by carving a canyon through these successive layers. The river canyon has also been affected by more recent events including massive landslides that blocked the river for a time some 10 to 14 thousand years ago and massive floods 3 to 4 thousand years ago. A substantial amount of the alluvial deposits from these floods remain unchanged to this day.

Railroad History - The railroad history along the Deschutes River is a tale of pioneering spirit and industrial ambition. In the late 19th and early 20th centuries, rail lines were laid along the river's rugged canyon, connecting remote settlements and facilitating the transport of timber, agricultural goods, and minerals. The Oregon Trunk Line, completed in 1911, stands as a testament to this era, carving through the challenging terrain and playing a vital role in the economic development of the region. Today, while much of the railroad infrastructure has evolved or disappeared, remnants of this history still dot the landscape, serving as a reminder of the transformative impact of transportation on the communities along the Deschutes River.

Lower Salmon River

4 Days - Hammer creek to snake river

August 25 - 28, 2024

Geology Focused with Dr. Gordon Grant

$1,629.00 (Adult)   

$1,579.00 (Youth - 7 to 12)

Geology - The Lower Salmon River winds through a deep, impressive canyon whose rock walls and valley deposits record over 200 million years of western North America’s geologic history. The ancient rocks tell a story of how volcanic islands and their associated assemblages of mud, sediments, and volcanic debris, were repeatedly rammed against the stable North American craton by plate tectonics. Over subsequent tens of millions of years these rocks were altered, sheared, cooked, tilted, uplifted and generally mistreated; this was followed more recently by massive incursions of Columbia River Basalt flows around 15 million years ago. The river has exposed this history, revealing the dramatic and picturesque landscape we see today.

Archaeology – The Lower Salmon Canyon is also the earliest known occupation site by humans in North America. The Cooper’s Ferry site, which we will visit, has recently produced artifacts and evidence of human settlement approximately 16,000 years ago. Here, people kindled fires, sharpened stone points and blades, and cooked large mammals. This evidence also suggests that the first occupants of North America traveled by sea and up rivers, at least 1000 years before melting glaciers opened an ice-free corridor through Canada. 

Rogue River

4 days - almeda to foster bar

September 11 - 14, 2024

Geology  Focused with Dr. Gordon Grant

$1,559.00 (Adult)

$1,509 (Youth - 7 to 12)

Arising in the Cascade Mountains, the Rogue River flows through the geologically young volcanic rocks of the High Cascades and the varied lavas and ash tufts of the older Western Cascades.  After entering the Klamath-Siskiyou Mountains, the Rogue carves a dramatic canyon through some of the oldest geologic formations in Oregon. Our trip will carry us through a chaotic mixture of metamorphic rocks, altered volcanic flows and marine sediments that have been folded, crumpled and slammed against the North American continent by plate tectonics.

The Rogue Formation, characterized by erosion-resistant metavolcanic rock such as quartz, serpentine and gneiss and is the most common in the canyon and is best illustrated by dramatic Rainey falls. The Rogue formation is interrupted by the Dothan Formation, characterized by sedimentary rock such as marine sandstone, siltstone and mudstone.  Mule Creek Canyon provides a dramatic example where the river finds an ancient fault line with the Dothan formation along the left and the older Rogue formation on the right.

Towards the end, the youngest and most easily eroded Flournoy formation emerges, comprised marine sedimentary rocks and conglomerates.