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The Vault - Fallout Wiki
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Fallout: New Vegas locations project
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For the location in Lonesome Road, see Long 15.
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The Long 15 (red)
Map MarkerNone
Part ofCalifornia
FactionsNew California Republic
Powder Gangers
White Legs
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Interstate 15, commonly abbreviated I-15 and colloquially known as the Long 15 is a pre-War Interstate Highway that passes through the former states of Montana, Idaho, Utah, Arizona, Nevada, and California, stretching from the border with annexed Canadian territories to San Diego County, close to the Mexican border.


Before the Great War, the I-15 was one of the most important freight routes, stretching from San Diego all the way to Canada. After the war, while much of the highway network eventually fell to disrepair, the I-15 remained a silent monument to the might of the United States. In the late 23rd century, heirs of the United States, the New California Republic, integrated the I-15 into the Mojave Campaign as the primary supply route into the Mojave Wasteland. The one hundred mile stretch of the Interstate passing through solid desert was filled with troops, traders, tourists, and travelers journeying to and from the Mojave and lands beyond. By 2281 it is the single most important strategic road in the Mojave, a lifeline for NCR forces deployed on the front against the Legion. The shutting down of the I-15 as a result of the NCRCF prison break in early 2281, caused by Powder Ganger attacks on caravans and the deathclaw infestation at Quarry Junction (caused by the Gangers when they stole the dynamite from Sloan)[1] has hurt commerce and limited military movements in the Mojave, as traders are forced to take a detour to New Vegas using Highway 93 through Nipton and Novac.[2]


The Long 15 begins all the way back on the Pacific coast, in San Diego (Dayglow), connecting it to the rest of the Republic. The most vital stretch of the I-15 in 2281 begins with the hundred mile highway between Barstow and the Mojave Outpost south of the Clark Mountain Range, before continuing into the Ivanpah Valley and the Ivanpah Dry Lake. It crosses into Nevada at Primm, then continues north through the desert, straight to New Vegas. Several small settlements lay on both sides of the Interstate as it makes its way north, including Goodsprings and Sloan.

It enters the Las Vegas Valley between Quarry Junction and Black Mountain, entering the city limits of Henderson and Las Vegas proper. It runs through a trench on the outskirts, before transitioning to an elevated highway near the Las Vegas Strip and continues in parallel until it exits Las Vegas in the northeast, near Nellis Air Force Base. It then continues towards Salt Lake City in Utah, passing shortly through Arizona, before continuing towards Ogden and further into Idaho, Montana, and Canada.


The I-15 appears only in Fallout: New Vegas


  1. The Courier: "Where'd the Deathclaws come from?"
    Chomps Lewis: "They moved into the quarry after the Powder Gangers came through and made off with most of our dynamite. We shut the quarry down while we waited for the NCR to get us some more blasting sticks, but now the Deathclaws have shown up. The NCR's a no-show, and my men and I have got nothing to do but sit on our asses all day. It's damn frustrating."
    (Chomps Lewis' dialogue)
  2. The Courier: "Did my attackers say where they were going?"
    Trudy: "They were having some kind of argument about it, but the guy in the checkered coat kept shushing them. Sounded like they came in from the north through Quarry Junction. If that's the case I can't say I blame them for not wanting to go back."
    The Courier: "Why is that?"
    Trudy: "That whole area's overrun with the kind of critters that just get mad if you shoot 'em. Merchants avoid that whole stretch of I-15 like it's radioactive. Which it could be for all I know."
    The Courier: "So where were they headed?"
    Trudy: "I didn't hear exactly, but the leader was talking about the Strip. Fella wants to get there and avoid the 15, he'd have to go east. Take Highway 93 up."
    (Trudy's dialogue)