When we returned to the campground on the afternoon of our last full day at Chaco we found that our cooler, left under the picnic table, had been stolen.  We reported it to the volunteer watchman, who was very apologetic.  A short time later, a Park Service lawman showed up, very polite and professional.  He wrote the details into a notebook, then drove through the area on the chance that the perpetrators were still around.  I was reminded of similar encounters in New York and San Francisco.