Old, but still active railroad trestle near abandoned Austin, MT. Just east of the Continental Divide in the Rocky Mountains.PIX4D model. Approximately 400 photos from DJI Phantom 2 V+. RTK ground control targets and total station measurements to bolts on towers made for tight registration of the cloud. Unused ground control checks within 0.15' xyz.
Also check video at
https://youtu.be/YqbBX4uV-Ug