一开始，阿罗由的村民会派遣一些人朝着13号避难所的方向四处侦察，帮助那些与自己有同样想法的人。但是随着时间推移，这样的活动愈来愈少，并最终停止了。The Vault Dweller taught the others the skills they would need to survive and grow strong. Hunting, farming, and other skills to feed them. Engineering and science to build their homes. Fighting to protect what was theirs.
The Vault Dweller and Pat led the village and the tribe. The tribe grew, and grew strong with their help. In 2188, their daughter, who later became the Elder, was born. Eventually, she and their other children became the leaders of the community.
On January 16 2208, several years after Pat's death, the Vault Dweller wrote his memoirs. Soon after that, he vanished from Arroyo and was presumed dead. The Vault Dweller left the Vault Suit behind, folded on the bed. Some say the Vault Dweller was taken by the sky spirits, others say that the Vault Dweller felt it was time to move on and leave the Elders to guide Arroyo to its destiny. After the One-Moon (Month) Cycle of mourning for the Vault Dweller ended, activity in Arroyo began to return to normal.
The final training of the Vault Dweller's daughter for the role of village elder began on February 2. She underwent a great deal of physical training and tutoring in various sciences, mathematics, and, of course, weapon skills. Two years later, she took her mystic test, a key ingredient of which is several pots worth of hallucinogenic plants from Hakunin's garden. She ran the gauntlet in the Temple of Trials, using her charm to pass most of the tests after her handgun jammed (and was ruined) on the first level. She offered numerous criticisms of the test, resulting in many revisions. Two days later, she ascended to role of Village Elder. She ruled with a steady hand, and her wisdom was greatly respected.
The Elder's son, later called the "Chosen One", was born on March 23, 2221. His father is not recorded in the tribal records. The reason for this is unknown, but the Elder may have simply been embarrassed.
In 2241, the worst dry season in many years causes a drought in the Northern California area, hurting crops and Brahmin in Arroyo. The Elder, having read a G.E.C.K. advertisement in her father's old holodisks, decides that her son must be sent to find it, as it is the village's only hope. On July 25, the Chosen One began his mystic test, descending into the Temple of Trials, just like his mother had many years before. Two days later, he left his home village to find the ancient device.
While the Chosen One was on his quest, on July 20, 2242, Arroyo was attacked by Enclave soldiers in vertibirds, wearing Power Armor, armed with energy weapons, and the villagers were captured and brought to the oil rig. Some of them tried to resist the attackers and were killed, and Hakunin was seriously wounded. When the Chosen One returned to the village, he found it almost completely destroyed and found a dying Hakunin among the dead bodies. Now, the Chosen One had a new quest - to save his people from the hands of the Enclave.
The Enclave needed the tribals for their FEV experiments. They needed two test groups: one of clean, pure humans and another composed of the "mutants" that lived all over the mainland, suffering radiation and FEV exposure for decades that, to the Enclave, made them unclean. The unclean sample was easily obtained by kidnapping the entire population of Arroyo. The clean group were the dwellers of Vault 13, who were reunited with their long lost Arroyo brethren in Enclave prison cells.
In Fall 2242, the Chosen One managed to enter the Enclave using a damaged tanker and destroyed the Poseidon Oil platform, killing the President of the United States and severely setting back the Enclave's plans for world domination. The surviving people of Arroyo and Vault 13 were free.
After the Enclave's destruction, the refugees of Arroyo and Vault 13 resettled, building a new community with the aid of the Garden of Eden Creation Kit. Finding themselves hundreds of miles from their Vault, the members of Vault 13 chose to join the villagers in establishing a new community, and their technical expertise, combined with the villagers survival skills, allowed the new settlement to grow and prosper. Two generations of the same bloodline were reunited, and their savior, the Chosen One, became Elder, presiding over the village of New Arroyo in the years to come. Certain that the safety of the new village had been secured and the new community was flourishing, his mother, the old Elder, passed away a few months later in her sleep.
It is very likely that the city eventually joined the NCR.
Arroyo appears only in Fallout 2.