Burning Man is the largest Leave No Trace event in the world.  Right now volunteers are doing the final sweeps to restore the desert back to a relatively pristine state so that Burning Man will be permitted to return again next year.  They have a cool map showing where they’ve found Material Out Of Place (MOOP).  Green means they were able to sweep through quickly, no MOOP.  We made sure to clean our camp space thoroughly before we left, happy to see it confirmed on their MOOP Map. 🙂