Four States Commonwealth

The  was one of the thirteen commonwealths of the pre-war United States of America. Created in the mid 21st century, it was comprised of the former states of Utah, Colorado, Arizona and New Mexico. After its destruction in the great war, this area became the birthplace of Caesar's Legion. Almost all of the area is under Legion control by 2281 and its capital, Flagstaff, is located in northern Arizona.

Known places

 * Bloomfield Space Center (Van Buren)
 * Boulder Dome (Van Buren)
 * Buena Vista (Fallout Tactics)
 * Bullhead City (Fallout: New Vegas Official Game Guide)
 * Dead Horse Point (Honest Hearts)
 * Flagstaff (Fallout: New Vegas Official Game Guide)
 * The Fort (Fallout: New Vegas)
 * Denver (Fallout: New Vegas, Van Buren)
 * Fountain Green (Honest Hearts)
 * Grand Canyon (Fallout: New Vegas, Van Buren)
 * Grand Staircase (Honest Hearts)
 * Great Salt Lake (Fallout: New Vegas, Honest Hearts)
 * Maxson Bunker (Van Buren)
 * Mesa Verde (Van Buren)
 * Nephi (Honest Hearts)
 * New Canaan (Fallout: New Vegas, Van Buren)
 * The Nursery (Van Buren)
 * Ogden (Fallout: New Vegas, Van Buren)
 * Ouroboros (Van Buren)
 * Phoenix (Honest Hearts)
 * Provo Bay (Honest Hearts)
 * The Reservation (Van Buren)
 * Rockville (Honest Hearts)
 * Salt Lake City (Honest Hearts)
 * Spanish Fork (Honest Hearts)
 * Syracuse (Honest Hearts)
 * Tibbets Prison (Van Buren)
 * Toquerville (Honest Hearts)
 * Twin Mothers (Van Buren)
 * Two Sun (Fallout: New Vegas)
 * Vault 0 (Fallout Tactics)
 * Vault 29 (Van Buren)
 * Zion National Park (Honest Hearts)

Utah Wasteland
As told by Randall Clark, at the start of the war Salt Lake City was hit very hard suffering thirteen direct nuclear blasts. He survived by fleeing to Zion National Park, where he had been hiking. He eventually returns to find the city "Mostly craters and warped steel girders where the buildings were." Unable to find the remains of his family, he returned to Zion National Park. Over the years, many people came to Zion due to its unspoiled nature.

In 2062, many Mormon congregations came together to purchase places in Vault 70, a Vault-Tec Vault in Salt Lake City. Vault 70 opened in 2190 and its residents use their three G.E.C.K.s to found the city of New Jerusalem in the ruins of Salt Lake City.

Most of the cities in Utah were destroyed in the Great War in 2077 and most of the state's current inhabitants are tribals (including the powerful Hecate of Ouroborus and the Blackfoot tribe). Burham Springs, with its horrible mutants is also located in the former Utah.

New Jerusalem's intolerant prophet and apostles repeatedly voted to have no commerce with outsiders from other, failed communities, refugees, or tribals. In 2233, a number of angry tribals, raiders, and disassociated attackers gang up on New Jerusalem and sack it, killing most of the Mormons in the process.

The new living prophet, Judah Black, led most of the remnants of the Mormon community north to Ogden, Utah. Where they establish the town of New Canaan.

The balance of power in the state is not clear due to conflicting information. Caesar claims to control most of "The Utah" Dead Sea mentions being from the "Great Salt Lake" and Vulpes Inculta is also from Utah. As both are in their thirties it's clear they have maintained a presence for sometime. However the extent to which they control isn't known but they are in contact with tribes throughout the state, and see them as prospect recruits.

Contrasting Caesar's view is the independence of New Canaan. Furthermore according to Jed Masterson, tribes like the 80's and the White Legs ravaged the I-15. Zion National Park, was independent as was Grand Staircase National Park, otherwise Daniel wouldn't consider evacuating them there. This shows that the western half of the state was more or less independent. However, a few months before the time of New Vegas, New Canaan has been destroyed by the White Legs. The White Legs a tribe local to the Great Salt Lake, they did this under orders from Caesar's Legion as they sought to join. Caesar ordered it's destruction to spite Joshua Graham, as it was his hometown. This caused the Mormons to scatter with the White Legs in hot pursuit, killing anyone affiliated with them.

Arizona Wasteland
Before the war, Mr. House, RobCo and Vault-Tec created a PDQ-88b securitron Vault under the future location of The Fort. After the war, Arizona was badly fragmented with each town fighting each other. Raul states it was so bad that you couldn't go two blocks without getting attacked. That was until the arrival of Caesar's Legion, formed near the Grand Canyon by two Followers of the Apocalypse and a Mormon Missionary. One follower proclaimed himself Caesar and took over the Blackfoot tribe and using divide and conquer and total war tactics took over everything around them between 2246-2271. The Legion conquered all of Arizona and established their capital in Flagstaff. The Legion returns to Arizona, if defeated at the second battle of Hoover Dam.

New Mexico Wasteland
The New Mexico Wasteland was taken over by Caesar's Legion. The Reservation is located here. It is likely that only North New Mexico due to their holdings in South Colorado.

Southern Colorado
The legion took over the southern area, and get their dogs from Dog City. The Legion controls everything up to and including Denver. If you win a series of barter checks in the final battle Legate Lanius will talk about how he led a brutal campaign to capture Denver, but the harsh climate, overtaxed supply lines and the lack of tribals meant the Legion couldn't restock their slave numbers. While the Legion eventually took the city, it was a Pyrrhic victory as Denver was no longer self reliant and now the Legion were now encumbered by it, in addition many more were killed than anticipated halting further expansion for some time, the memory left a bitter impression in Lanius.

Appearances
Parts of the former Four States Commonwealth appear in Fallout Tactics and Fallout: New Vegas and its add-on, Honest Hearts. Most of the places in Van Buren and Fallout d20 were located there as well.