The Buttermilk Trail. Photo by John Field

May 29, 2018 – Like a surgeon, the South Yuba River has cut an incision across the Sierra Foothills topographic surface to expose the inner anatomy of the Sierra Nevada.  The 20-mile long scenic river canyon within the park provides a cross-section of the ancient oceanic-continental tectonic plate boundaries of the area during Jurassic and older times.  

A new program in the park this year is a guided walk along the Buttermilk Bend trail that points out the interesting geology of the South Yuba River State Park. 
Prior to the walk participants will receive a brochure about the local geology as well as hear a short presentation about the four major tectonic belts (assemblage of rocks that have been folded or mixed together) present within the state park boundaries.  Also discussed in the presentation will be some of the plate tectonics concepts used by geologists to interpret the complex geology of the area.  
On the walking tour, you will learn about the rock types along this portion of the South Yuba River as well as observe first hand some of the geologic features associate with the area’s complex geology.  The guided walking tour and short presentation are expected to last from two to two and a half hours. 
Interested?  Please contact Karen Synowiec ( or Bob Slyker (
What: Geology Walk at South Yuba River State Park
When: Sunday, June 3
Time: Meet at 1PM in Bridgeport’s north parking lot