The brahmin pen is located in the eastern sub-section of Shady Sands. To the south are the town's well and the garden.
Normally, there are only five brahmin in the pen at any given time. Originally, the town didn't have any brahmin, because they could barely afford to feed themselves. However, after the small group of people from Vault 15 established themselves as Shady Sands, and the G.E.C.K. was used to institute fertile fields, enough food was produced to trade for and raise cattle.