Dark Sky day 3

The sky is definitely dark at the moment, it's thunderstorming overhead right now. We did a hike today to a place called 'Sand Caves'. Some climbing was required. We were told, and we don't know if this is true, the caves were dug, and the sand harvested, because NASA wanted that particular type of sand to make the glass that was used in the windows of the Space Shuttle. I'm skeptical but that's the story. We got in 15 holes of disc golf before the thunder and lightning started to get uncomfortably close. We almost made it back to the car. Almost. We move further south into Arizona tomorrow.