- "Yerkes had been fairly obstreperous at times, but at least broken in."
- ―Cordelia Vorkosigan's opinion of leadership of Kareenburg[src]
Yerkes was the Mayor of Kareenburg on Sergyar. He very much did not want to have the capitol moved away from the town despite the danger to the region from a nearby active volcano. He had very little success getting information from Admiral Jole about plans for a second military base on the planet (which he correctly deduced would be placed near the intended future capitol).
Shortly into the tale, Mayor Yerkes lost his re-election bid to new-Mayor Kuznetsov.
- Gentleman Jole and the Red Queen, chapter 2, mentions in chapter 12