Dear Debbie, It is interesting that you did not buy your cordovan queens. The cordovan gene was widely used years ago in the Starline program as a genetic marker, so it was widely distributed. If you don't have any other bees in the area, say three to five miles, your bees may be mating fairly pure. If you have 25 colonies, you shouldn't have much of a problem with inbreeding since you bees are mating naturally. As you may have read, one of the first signs of inbreeding in a honeybee population is a very spotty brood pattern. This happens because the frequency of lethal genes increase, which are not visible to you, but are detected by the bees in the developing larvae. The bees then remove these larvae which makes it appear as if the queen is laying poorly. If you do have an isolated location, you can easily increase the frequency of the cordovan gene by selecting queens with the cordovan color as 100% of here drones will be cordovan. I work with the light cordovans down here in Ohio, but I use instrumental Insemination to maintain pure light cordovans. I'm always interested to here about other people with cordovans because there are so many interesting things to do with them. It is always fun to pick out your bees working on the flowers. Sincerely, Joe Latshaw