I imagine that the work required to build this wall would have been both intellectual and physical. It would have been hard work to haul the rocks around and stack them up, but I don't think it could have been done quickly. It would have required time, observation, and reflection, a careful sussing out of the characteristics of individual rocks.
Even though we don't typically build rock walls to keep our livestock in anymore, we still need rock structures, and I am seeing them everywhere. I also found this culvert on a different hike at Bowman Lake. This one wasn't constructed quite so carefully, and the rewards of closer inspection are those of introspection about technology and the state of craft and skill.
I don't know anything about how a structure like this gets built. It looks like it requires machines, probably powered by fossil fuels, and the skills involved are those required to operate the machinery, rather than the careful consideration of a natural material. I also suspect that the wire frame is assembled elsewhere, possibly far enough away to require a very significant investment of more fossil fuels to transport.
There is also this: a lovely stone wall and a set of steps in my neighborhood. The gentleman who lives here and maintains this wall is not young, but he is hale. I took several walks in the neighborhood and I watched his progress over a week or so. It looked like thoughtful work, and I think the result is lovely. After the wall was finished, I noticed him up on his roof, pointing his rock chimney.