Yampa River Geology Trip 5 Days


OARS Guide & Geology Expert,  Zac Williams

Dinosaur National Monument – the name alone conjures a host of images: dinosaur bones preserved in ancient rock walls, deep rivers that cut indecorously through dry desert canyons, ancient sea beds full of prehistoric fossils, frozen in time. Join OARS guide and geology expert, Zac Williams for an in-depth exploration of these wonders of the evolution of the Earth.

Zac is a second generation river guide and a graduate of Utah State in Geology. He brings both his passion for river guiding and his love of teaching geology to our Yampa River Geology trip in Dinosaur National Monument. For Zac, looking at geological formations is like reading a history book of the planet with each rock telling its own story. “Geology has inspired me to see the world differently. Every trip down the Yampa feels like a journey into the past—both in the geologic sense and the personal sense. It’s where my parents met and where some of my greatest life memories were formed.”

Yampa River rafting
Rafting through layers of time on the Yampa River

Overlooking the river as it flows through Dinosaur National Monument

As you descend the Yampa River, you have the fascinating experience of actually traveling through the river canyon’s various layers, each one representing an entire age of the earth’s development: the rise and fall of major mountain ranges, the arrival and retreat of oceans at least 12 different times, the alternating development of deserts and swamplands. A billion years are captured in these canyon walls, along with the remnants of various life forms that existed long before humans. Our pathway through time showcases some of the oldest exposed rocks in the world, ones that have been folded, lifted and split by eons of geological forces.

Blonde rock and black manganese oxide on Tiger Wall

Beside this fascinating scientific value, the Yampa’s geology is also responsible for the beauty of its canyon home: vertical yellow and red sandstone walls that tower as high as 1000 feet and squeeze the river through a surprisingly narrow gorge, tiger-striped walls alternating in blonde rock and black manganese oxide, clear creeks tumbling out of shady side canyons, sheltering sandstone caves, and more…


Geology formation near the Yampa River

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