It started at the inauguration, when the uniformed protectors of America’s front lawn took in the sweep of humanity at the National Mall. It seemed obvious that the crowd for President Trump was not nearly as large as that for Barack Obama in 2009. Somebody in olive green retweeted the obvious, using comparative pictures.

This small act of historical clarification by the keepers of our sacred sites and shared spaces would have been no big deal, had not the response from the new president sounded like an edict from the Dear Leader. A gag order on public servants was issued, and the National Park Service tweet on crowd size vanished, replaced by a picture of a bison.

But then, flares of defiance! The response to the dawning realization that a crazy man had taken over the White House was truth. From Badlands National Park came a tweet about more carbon dioxide in the atmosphere than any time in the last 650,000 years. From the Redwood park, a note about the saving grace of ancient trees. From Death Valley, a reminder that Japanese-Americans had once been interned there.

Heroes in uniform? No, not by normal standards in normal times. Informing people is what park rangers do. Anyone who has ever listened to a narrative of what happened on the bloodiest single day in American history at Antietam National Battlefield, or heard an explanation for the geysers at Yellowstone, can appreciate the professional knowledge.