When Susanville incorporated as a city in 1900, its eastern boundary was Weatherlow Street. In 1920, annexation of Halltown and the East Addition was discussed, but no action was taken. With continued growth east of the city limits annexation efforts failed. In 1947 that finally changed when voters approved an annexation. The City’s Main Street now extended from Weatherlow to Fairfield, and additional eleven blocks.
Everyone had guessed what the Greater Susanville population was, but no one knew exactly. After the approval of the annexation, the City requested the U.S. Census to conduct an official count. This was important, for the City needed that information to provide it to federal and state authorities for allocation of tax funds based on population. A census was conducted on April 30, 1948, and it showed there were 5,358 inhabitants.
In 2023, the population was 11,593.