Regular Tom is a geyser located in the middle of Bone County in Grand Theft Auto: San Andreas. The geyser is a reference to the famous Old Faithful geyser in Yellowstone national park in Wyoming which is weird since the location is based on parts of California and Nevada which has no geysers.
The geyser functions are simple bursts of water that spout out of the top of the mound. The player will not be injured or affected in any way if he stands atop it.
Many myths have been reported in and around the geyser such as Mr. Trenchcoat and the infamous Mothman. The geyser has also been linked to the Epsilon Cult, as the shape of the geyser as it appears on the map is reminiscent of the Kraff descendant birthmark; because of this many players claim the geyser is a possible "Pass" (reference in the Kifflom, the GTA San Andreas teaser website states: "Travel through the dawn to the pass pictured in our brochures"). The area of the geyser is located between 2 large Mesas, so it is geographically considered a pass.