Regular Tom is a small isolated geyser located in the heart of Bone County, San Andreas. It sits at the base of The Big Ear, and is frequented by tourists and locals alike. Also nearby is Area 69, the Sherman Dam and Las Brujas. It's jet of superheated water can be seen regularly, giving this hot spring its name. Although seemingly powerful, the jet blast is incapable of physically affecting the player or others. This is the only geyser in the entire state. It's name and likeness are a parody of the Old Faithful geyser in Yellowstone Park.
This is one of many locations within the game that serve no storyline purpose but exists to provide additional color and detail to the game world.