Brilliant composition, here. The flow of the lines over the land is really beautifully rendered—you chose your vantage point perfectly.

As for the polarizer, I'm thinking .. ND grad or possibly a software effect? John?

Yes to the polarizer but it still was not enough. The sky was blown out. Hazy clouds that really over powered things. The effect is Lightroom's graduated filter pulled down to the skyline. I can do almost as well without the graduated filter but I wanted to play with it to see what it can do. I wish I had tried a Cokin ND grad while I was on site so I could compare.