Prior to the United States' official entry into World War II, the United States Marine Corps made the decision to site a training ground for field and anti-aircraft artillery units in an area accessible by aircraft taking off from carriers near San Diego.
To create the training base, 631.345 acres (255.496 ha) were obtained.
The government announced that the base was to be named after Brigadier General Robert Henry Dunlap, U.S.M.C. After construction of Camp Dunlap was completed, it was commissioned on October 15, of 1942.
The camp had fully functioning buildings, water, roads, and sewage collections.
The base was used for three years during the war.
By 1949, military operations at Camp Dunlap had been greatly reduced, but a skeleton crew continued on until the base was dismantled.
By 1956, all buildings had been dismantled, but the slabs remained.

As of October 6, 1961, a quitclaim deed conveying the land to the State of California was issued by the Department of Defense as it was determined the land was no longer required.
The deed did not contain any restrictions, recapture clauses or restoration provisions.
All of the former Camp Dunlap buildings had been removed.
The remaining slabs were not proposed for removal.
Later, legislation required that revenue generated from this property go to the California State Teachers Retirement System.

Leonard Knight, an early settler who created the Salvation Mountain art installation, was featured in Sean Penn's Into the Wild (film), released in 2007.
An obituary of Knight stated that he "spent almost 30 years building the colorful mountain ... Built out of adobe and donated paint, Knight worked on the mountain all day, every day.
He even slept at the mountain's base in the back of a pick-up truck, with no electricity or running water".

An article in Smithsonian magazine in October 2018 referred to the community as a "Squatters’ Paradise" which locals consider to be "one of America's last free places".
The article said of the population: "There are clearly people there who don’t want to be found, so there’s something about disappearing, and the desert offers that kind of opportunity".
A news item in April 2020 stated that Slab City "lacks infrastructure such as running water or electricity.

A brief documentary film in 2019, "The Last Lawless Land in America: Slab City", provided an insight into the settlement, its art works and residents. (
A Flutter Brothers Production, 
created by Chris Parr and Harris Dirnberger).
According to the producers, "the land is officially owned by the state of California, so state and federal laws still apply, but officials seem to have no interest in dedicating resources to enforce them".
Prior to the United States' official entry into World War II, the United States Marine Corps made the decision to site a training ground for field and anti-aircraft artillery units in an area accessible by aircraft taking off from carriers near San Diego. To create the training base, 631.345 acres (255.496 ha) were obtained. The government announced that the base was to be named after Brigadier General Robert Henry Dunlap, U.S.M.C. After construction of Camp Dunlap was completed, it was commissioned on October 15, of 1942. The camp had fully functioning buildings, water, roads, and sewage collections. The base was used for three years during the war. By 1949, military operations at Camp Dunlap had been greatly reduced, but a skeleton crew continued on until the base was dismantled. By 1956, all buildings had been dismantled, but the slabs remained.
As of October 6, 1961, a quitclaim deed conveying the land to the State of California was issued by the Department of Defense as it was determined the land was no longer required. The deed did not contain any restrictions, recapture clauses or restoration provisions. All of the former Camp Dunlap buildings had been removed. The remaining slabs were not proposed for removal. Later, legislation required that revenue generated from this property go to the California State Teachers Retirement System.
Leonard Knight, an early settler who created the Salvation Mountain art installation, was featured in Sean Penn's Into the Wild (film), released in 2007. An obituary of Knight stated that he "spent almost 30 years building the colorful mountain ... Built out of adobe and donated paint, Knight worked on the mountain all day, every day. He even slept at the mountain's base in the back of a pick-up truck, with no electricity or running water".
An article in Smithsonian magazine in October 2018 referred to the community as a "Squatters’ Paradise" which locals consider to be "one of America's last free places". The article said of the population: "There are clearly people there who don’t want to be found, so there’s something about disappearing, and the desert offers that kind of opportunity". A news item in April 2020 stated that Slab City "lacks infrastructure such as running water or electricity.
A brief documentary film in 2019, "The Last Lawless Land in America: Slab City", provided an insight into the settlement, its art works and residents. (A Flutter Brothers Production, 
created by Chris Parr and Harris Dirnberger). According to the producers, "the land is officially owned by the state of California, so state and federal laws still apply, but officials seem to have no interest in dedicating resources to enforce them".
Slab City, California