How many of us will take a drive in the country, catch a glancing view of a spinning windmill, and smile?

For people of a certain age, windmills may take you back to your childhood days, when you think about the spinning sails — in need of oil — making that sound with each rotation. It’s always a good memory, and it turns out — reason enough to keep the old windmills working. So an army of specialists is fanning out across America, saving windmills built in the 1920’s — and installing new mills made to look just like the old windmills. This is their story as we preview Icons of the American West.