They used the gigantic dump trucks to haul a bunch of those 7' x 7' boulders to the end of the new road where they were "placed 1 at a time" by a huge tracked Drought (those long limbed digging machines that can pick up the boulders 1 at a time if they have the claw attachment that acts as the machine's thumb to clamp the boulder into the bucket) to create the road bed. Then they dumped the next levels of rock etc and pushed it into place with the very large Caterpillar Bulldozer. It's all very tedious work but makes an excellent road bed, I was told.