There is another "tom's creek" closer to DC. If the drawn map is accurate, and it can be matched and found easily on google maps (I'm skeptical) I'd guess it was in MD rather than southern VA just because it's closer and socially more DC-ish than Southern VA. What exactly is there to check out though? Human DNA in pig feces? Here's the MD farm I found that matches close enough to the drawing. The website says they don't have pigs for sale currently but the satellite image shows pigs. There are also many more pens in this image than in the Hoof-hearted farm image (which more closely matches the whiteboard drawing). Still it takes many leaps in logic to get here from the dry erase board, just saying.

Google maps Archived

Edit

Archived from Bing I'm more convinced that this is the place in the drawing now. (Not that it has any nefarious connection to anything) but after looking at it on Bing maps with the aerial view, you can see which pens hold hogs and which ones hold chickens. The drawing has "welsummer" and "americana" and "marans" labeled on there which are chicken breeds, and the locations match with the aerial photos from bing