Glen Canyon (Part 3)

Geography and engineering.
Source: OPERATION GLEN CANYON
by National Archives and Records Administration
Publication date 1961
Usage Public Domain Creative Commons License

Audio used:
Music: Sleep/Meditation (Fall Asleep) by Alexander Nakarada (www.serpentsoundstudios.com)
Licensed under Creative Commons BY Attribution 4.0 License
https://creativecommons.org/licenses/by/4.0/