These rare, pre-War artifacts are widely considered to be useless baubles, but rumor has it that a certain important collector will pay handsomely for them.
Location[]
Salida del Sol North, in the upper levels near Dean's Secret Stash. From the southern-most entrance to Salida del Sol South (in Salida del Sol North), proceed down the stairway to the streets and head east. Go up the first staircase and take the rooftops west on the lefthand side. Enter through the hole in the wall. The Snowglobe will be on your left atop a crate.
Because you receive Sierra Madre chip instead of caps, they can be cashed at the Sierra Madre Resort & Casino for 2000 stacks of pre-war money. These in turn can be sold at 100 barter for a total of 18,000 caps, making this by far the most valuable snow globe in the game.
The Sierra Madre snow globe does not have snowflakes. Inside it only shows the recognizable Cloud.
If you plan on finding this snow globe, do it BEFORE you return to the Mojave Wasteland or else it becomes impossible to attain as you cannot return (without the use of console commands; see here for more information).
Bugs[]
Xbox 360 Sometimes the Snow Globe does not appear before completing the add-on. The Globe should appear after exiting the vault.
Xbox 360 If the Snow Globe does not appear on top of the crate, then look around as it may appear on the ground next to the crate.
Xbox 360 If the Snow Globe still does not appear, it may have spawned behind the crates it's on top of. This can easily be remedied by throwing a grenade into the space behind the crates- it should be flung out from behind them by the explosion.
Sometimes the Snow Globe does not appear before completing the add-on. The Globe should appear after exiting the vault.