Bring your truck out here and just back it up to a canyon wall. You can get all of the rocks of any size that you want free. Every small quake, Cal Trans has to go over the highway between Redding and the coast and clear the rocks off the road. On one of your motorcycle trips you need to come out here and go to Sequoia and Kings Canyon Parks and see some real trees. Then you can come on up North and see real canyons that do not rival the Grand Canyon as I have never seen any that are like it. If you want to feel at home for a while, go to Southern Calif., and out where the desert is flat. China Lake is a good place as that is where they used to do the racing and speed runs before the Salt Flats.
Ron