Feral queen without swarm?

Do feral queens ever venture out of the hive outside the context of a swarm? Maybe ousted from her hive? I swear I saw a bee on one of my corn stalks that was too big to be a regular worker, but she disappeared before I could grab my phone or anything to put her in. I was hoping I could get her to take up residence in a hive I wasn't able to get bees for (or bait). Maybe it was just an especially large worker, but I was hoping someone more experienced could shed some light.

In addition to worker bees and queen bees, there is also drones.
Not all bees are honey bee, there is over 16,000 different species of bees, so its very possible that you saw another bee species.

Or possibly it was a queen on her way back from the mating place and was exhausted?
Hard to tell if there is no picture.

Extremely unlikely it was a queen. They don't leave except for one mating flight when they're young or with a swarm when they're older. Even if it was a queen she wouldn't survive very long without attendant bees. Probably for the best that you weren't able to capture it.

Although I have worked with bees for years,  I am a long way from being a expert. It is my understanding that rejected queens are normally killed off.  

there is lots of great info on the internet on how to get wild bees into a box for domestication, basically build trap boxes and bait them with a drop or 2 of lemongrass oil and hang them up around an area where you see bees working