I was aware of these kind of small airports but had never been to one. As we took off from Girdwood airport, we circled once over this small bright color (almost looking like a DHL brand) airplane getting ready to take off. Notice something about the runway? It does not have asphalt on the top. It is a dirt road runway. I had heard of these runways but saw it for the first time. (Also, it is a very short runway – only 2,100 feet).