A very minor character in The Long War who chose the wrong career and who is used to lampshade a defining event. Two days into his new job as a Yellowstone park ranger, he is first seen seeking to pacify a family of tourists who are disappointed that the geyser Old Faithful has suddenly, mysteriously, chosen not to be faithful any more. As puzzled as anyone else, he has the job of calming typical inhabitants of Power Cable, Nebraska*, who are angry that the spectacular thing they promised little Virgilia on her ninth birthday did not, in fact, happen, and they are treating Herb as if he were personally responsible.
Herb perhaps takes this to heart, as later in the book we learn he was too close to Old Faithful when a long-delayed eruption of unprecedented power and fury turned him into a cloud of pink steam not unlike a hapless rail engineer who read his sliding rule upside-down. This of course heralds the cumulating event of "The Long War" and its consequences in "The Long Mars".
(*Note: Mr and Mrs Virgil Davies and their daughter Virgilia are in fact from Los Angeles, but for the purpose of this narrative, "Power Cable, Nebraska", suggests a certain type of United States citizen. The sort who, in real life, tried to pose their kids with an adorable cute l'il bear cub for photos, and were surprised when the mama bear ripped the kid's arm off. They then tried to sue Yellowstone for not keeping its animals under control. True story...)