Very nice Motoadve. I know some of the rivers drain gradually, but could you mention, in future videos, when you are talking off down drainage. One ways are pretty obvious, in the mountains, but down drainage consideration is an energy/safety thing that should stick in the pilots mind. Looking toward distant high mountains gives the illusion of looking down drainage. In high desert mountains water is not always there to indicate, but the wine glass method on a topo will indicate down drainage.

Keep up the good work.