Lidar and photogrammetry is pretty remarkable at showing manmade structures despite vegetation. When you see the non-colored points the lines become very apparent. On my ranch I had phone line run and they took a dozer and created a path the trench along. After 10 years of the brush and grass growing up it was pretty much indistinguishable to the naked eye. A drone flight and review of the point cloud made the dozer path stand out like a sore thumb although it was still impossible to see in the pictures.