Groebner also ran into one of the more dangerous native plants- poison oak. There is significant poison oak at the boulders. Even the leafless branches in the winter can cause highly allergic reactions. Be aware of what it looks like- leaves of three let it be! It's shiny and color and needs to be avoided at all costs!
Please be aware that the bouldering is at Columbia College and Columbia State Park. Be respectful of the landowners. Occasionally at the Stage Coach Boulders, the staff may ask climbers to step out of sight while they performed pretend robberies on the stage coach.
Here's some footage of a Touchstone setter and Columbia developer Ben Polanco, as well as Menesha Mannapperuma, and guide book author Dean Fleming climbing at the boulders.
Here's some more footage by Dean Fleming of the bouldering.
Fleming's guidebook "Columbia Bouldering" is available at the Touchstone gyms. Check out the great pebble wrestling in Gold Country.