How do you "build" a rockcrawling trail? After all, there aren't any bushes to clear, and the route already follows the bottom of the canyon. The idea is to establish a beaten path, and to fill in just enough holes to make the trail passable, albeit passable with substantial difficulty. Shovels are useful for filling in small holes with fine-grained gravel. Moving big rocks requires hefty crowbars, cooperated muscle power, and sometimes a winch. Safety is paramount: Everyone needs to be warned when a big rock is about to be moved.