The outside is patrolled by many blind deathclaws and young deathclaws. The office building is occupied by three giant ants, whose bodies may or may not contain ant nectar and/or an ant egg or two. In addition there are ten ant egg clutches, most of them containing ant meat.
Sunset Sarsaparilla star bottle cap on the desk in rear of the Gypsum quarry office. There is a large possibility for this star bottle cap to find itself thrown around the room and with the possibility of becoming lost during the inevitable battle with residing ants in the confined space within. It may also clip through the desk, at which point it is impossible to retrieve without console commands or lucky explosives usage.
There is an unmarked train tunnel (with a Very Hard lock on both ends) north of the train yard that leads to Nellis Air Force Base and may be used to avoid the howitzer bombardment when approaching the Boomers' base.
Gypsum train yard appears only in Fallout: New Vegas.
PC Playstation 3 Xbox 360 The Sunset Sarsaparilla star bottle cap does not always appear. Reloading from a previous save may fix this. Alternatively tossing a frag grenade into the area of the desk (with the dead terminal) seems to shake it loose and make the bottle cap re-appear on the desk.[verified]