The path of Killen Creek Trail is composed of mystery dust. It looks like sand but behaves more like very loose dirt, or even ash. If you stomp your feet or kick up the dirt, it produces a fine cloud. My educated guess is that movie effects specialists come here to get the mystery dust for use in generating smoke and dust visuals in some of the top movies of the day. That is why the trail appeared so dug out compared to the surrounding ground level.