I have looked at your site on a couple occasions before and have always enjoyed your techniques you have used. I am also a mountain man, I do concrete, Wow the Rocks you have handled brings back memories of my youth being raised on a farm. I have picked up more rocks than what you have, But when emptied off the wagons, mine turned into rock piles, yours turned into an awesome form of ART. You are a real skilled artist, you have taken what most people consider to be nuisance and make a Rembrant.
I really appreciate your artwork more than I do a Rembrants Painting, not to offend any rembrant fans.
Keep up the GREAT Work
Yes, the rocks are all mortared together. The hill is composed of old sea bed and is very hard, almost like sandstone. In fact I had to use a chisel on some areas! I cut "steps" into the hill, so that the rocks are supported by this hard sediment. The steps are also sloped back into the hill a little, so that the weight of the rocks leans into the hill rather than away from it.
Most of the mortar is put in behind the rocks, and any excess that squeezes out between the rocks is hosed off with a light spray. This minimizes the appearance of the mortar. In addition, the mortar is tinted to help it blend in with the rocks.