From Halopedia, the Halo wiki
Some of the cities engulfed by the spread of Seattle, such as Kirkland, retained their names as subdivisions of the sprawling metropolis. Kirkland being also home to 343 Industries' 434 Combat Readiness Lab, where the manufacturer tested its FOTUS-class Mjolnir. Downtown Kirkland is known for "rough and tumble" streets, and the surrounding area is frequently overcast and frigid, making it seem like Winter for nine months out of the year to some.
Government and society
Seattle hosts a number of competing corporations which frequently engage in corporate shadow-wars with one another. The aforementioned FOTUS armor had proven invaluable during some of these conflicts.
The companies located in Seattle are 343 Industries, whose FOTUS-class Mjolnir armor was partly hand-crafted from the finest locally-sourced materials. Chalybs Defense Solutions also maintained a presence in the city, either manufacturing or testing the MLRS-2 Hydra there.
Seattle possesses the highest per-capita number of coffee dispensaries in all of human-occupied space. Records of the area surrounding the 434 Combat Readiness Lab specifically indicate that there are enough coffee and congealed sugar dispensaries for each resident to have their own. Unified Earth Government administrative agencies have been alerted to the anomalous distribution of these facilities.
List of appearances