Timeline

2253 With radiation storms easing and new routes discovered towards East, increased trade and expansion of NCR allows wastelanders to undertake greater construction projects. Arroyo Excavation Co. is founded with partners from San Fransisco and enterprising Klamath merchants by the Elder of Arroyo, with Chosen One, as its symbolic CEO. Its official mission is scavenging useful machinery and materials to be recycled or restored. While competition is stiff, using 13th tribes fame and combined technology of Shi and Arroyo residents, Arroyo Excavations earns contracts for NCR and operates for the interest of North Western people.
2256 Arroyo Excavations Co. successfully clears and transports a fusion reactor from ruins of Mariposa ruins to Arroyo, after driving out a band of raiders and mutants. Encouraged by their success in the hazardous nature of ruins and fewer then expected causalities during disposal of remaining FEV spillage, Arroyo Excavation CO. attempts salvaging Oilrig ruins. Both a personal quest and the original intent of Shi partners. However project is nixed by NCR and BoS, as well as lack of proper equipment. Oilrig excavation is shelved indefinately.
2260-4 Chosen One is blessed with a grandchild [PC].
2267 Arroyo Excavations Co. loses Shi partners due to lack of progress on Oilrig excavation as well their desire to maintain their distance with NCR. Companies operation area shrinks to local and contract work along coastline.
2271 [PC] starts informal education with a friend of Chosen One from BoS, a senior scribe who went AWOL during NCR-BoS war.
2271 Mojave Express and Mojave Outpost established, Governors of Hub and New Reno makes sure one of the supply stations along I-15 is located off the highway all the way south of I-40.
2272 Despite protests from Planning Committee location of Outpost 13 further south with blessings of NCR Army. It is seen as a move by NCR Army using Caravan companies and New Reno families to secure a black site.
2272 A Ghoul salesman Aldous hears about a well preserved television factory in vicinity of Outpost 13. He and a group of Ghouls pool their fortunes to start manufacturing Television Sets.
2273 As demand for heavy duty machinery and hard to produce components for railroad project along I-15 gains traction, so does Arroyo Excavations contracts. The fame of 13th tribe attracts the most dangerous and expensive contracts.
2270?? Micheal McKing, a New Vegas local marries with a -Brahim Barons- daughter, as a dowry they are given a decrepit Ranch bordering New Adytum and a barely habitable Mesa and enough life stock to start while his sister-in-law gets a much better fortune in Mojave.
2274 NCR signs the New Vegas treaty. With influx of travelers and workers to build railroad Outpost 13 sees a lot of traffic, but as the railroad progresses it rapidly becomes desolate.
2275 Outpost 13 contiunes to house several important people across NCR and New Vegas doing important things, such as "gun trade which will be sanctioned in near future" and "unconventional pharmaceutical joint research". Before rumors of things talks taking place become public knowledge, Outpost 13 becomes a short lived Followers Of Apocalypse Mental Hospital, before NCR cuts its ties and form OSI. Hospital never opens.
2276 Arroyo Excavations shows interest in Outpost 13. However while its original proprietors are interested, NCR Senate and Army pressures against it, having different plans for the region.
2276 With Legion making appearances and situation in Mojave deteriorating the last trader leaves Outpost 13. General Lee Oliver orders 13 be used as a forward observation and logistics base, while Senate overrules Arroyo Excavations repeated attempts to purchase Outpost 13.
2277 Chemical Plant is partially restored and staffed by Powder Gangers with “connections”. Starts producing explosives and small arms munitions of dubious quality becoming an unofficial supplier of NCR troops in Mojave. Outpost 13 is where middlemen handle the trade between corrupt NCR officers and mysterious Chem. Plant owners.
2277 First Battle Of Hoover Dam makes it clear the war with Legion will end on Hoover Dam, which results in Outpost 13's use as a logistics base unnecessary. Still a platoon is left behind to observe I-40, while Legion infiltrators and spies use the road with no impediment when they wish, completely unaware of the  important trade going on.
2277-9 Platoon stationed at Outpost 13 gradually becomes a three man "special ops sentry squad" to maintain illusion of NCR taxes being spent wisely. Meanwhile rarely visited Outpost 13 is "guarded" by a fallen out of grace Mordino Mademan and his two thugs, the worst NCR Army has to offer.
2277 [PC] is sent to study in Boneyard with Followers Of Apocalypse. It is not clear how he graduated, out of courtesy or [PC] was really good at subjects.
2278-82 Aldous finds it impossible sell televisions. Interest vanishes as only porn and education material is aired with little coverage, combined with war economy and cheaply refurbished units doing just as well. The factory is renamed to Cathode-Ral Research Center and starts research to develop new products with resources at hand.
2279 Micheal's sister-in-law, loses everything when their Brahmin Baron father stopping runs to New Vegas find it hard to make it in Mojave and move in to Micheal Ranch.
2281 With the Second Battle Of Hoover Dam drawing near Outpost 13 is all but forgotten except for the occasional runner checking in. Who only does drugs, crash for the night and return to his unit giving the exact same report which nobody reads.
2281 With NCR defeat Chemical Plant is abandoned by its shadowy partners, stranded criminals however find new black market customers. Chemical Plant residents are divided into Union and Detonators. With former still keeping their jobs, while Detonators become guards and mercenaries with little prospect and nowhere to go.
2281 During Senate talks after Second battle Of Hoover Dam Arroyo Excavations CEO in office, Kal, son in law to Chosen One, exposes merchants from Hub, every single New Reno family member profiting off of war, naming several politicians and Army officials relationships with these people and gives an "not yet corrected account" of General Lee Olivers short flight off the Hoover Damn. This hearing was being broadcasted live across wasteland.
2281-2 Chosen One, calls all favors he is owed to allow Outpost 13s purchase. With Legion lost its capacity to make war across Colorado river and the political controversies, he forces [PC] to settle in relative safety of desolate 13 from Boneyard.
2281 Numerous riots are surpassed by efforts of Kal and NCR police. Despite seeking a peaceful resolution, through resignation of NCR government and new elections Kal is made the much needed scapegoat by NCR.
2281 Great Bar Fight takes place near Boneyard University, when a retainer of Chosen One, Harvey, tries to convince his grandchild to start his job at Outpost 13. Great Bar Fight, which lasts three days, becomes a stuff of legends when the argument between two 13th tribals spiral out of control, involves NCR Army Officers on leave, local political dissent, police forces and two Deathclaws. Ultimately ends with local authorities presenting a Medal of Courage when [PC] saves the bar from Deathclaws.
2282 [PC] wakes up at New Adytum – Mesa Borderstation, tied up in a caravan cart, gagged with Medal Of Courage and a very tired Harvey.