I just finished this one - I only had a pencil drawing when we left the mountains on October 19th.
And I'm also late joining the AEDM crew over at Creative Every Day. Thanks to Linda at Vulture Peak Muse for enticing me into this with her own contributions.
One evening, coming back from the Black Mountains, we were playing peak-a-boo with the rising full moon. It kept appearing around hills and over edges. That probably put this into my head.