We did have help getting the gravel down into the pit, but it was still a huge amount of shovel work. Gale, the excavator we worked with, was up on top in the parking area using a Bobcat to dump loads of gravel down into the pit, while Bruce and I stood down there (jumping out of the way as appropriate) and then shoveling and pushing it around to cover the drain tile evenly.
Some of it had to be carried down in 5-gallon kitty litter buckets because the Bobcat could not get to the east side. At left, you can see me shoveling some of it into a bucket, getting ready to carry it down the steep hillside and dump it into place. I carried (and dumped) about 15 buckets of this stuff to the east side. By the end of a very long, hard day, we had the gravel down in the pit alongside the structure. We were able to put up some more pebble board.
After the gravel was down, we had to cover it with a layer of gauzy landscape fabric, to keep the dirt and sand from filtering into the clean gravel. Then Gale started the backfill process--dumping and pushing sandy, gravelly fill on top of the fabric-covered pea gravel. It is quite a process, and one about which I knew nothing before this. And I don't want to learn any more! Below are a few shots of our little beauty, with its walls covered in pebble board and the backfill coming along nicely.