Records of the Basin, Montana, post office include cash books (1902-1917); postmaster's account and record books (1900-1917); registers (1899-1916, 1923-1931) of money orders issued and received; register (1905-1919) of notices to publishers of removed and unknown addressees; registered mail receipts (1908-1922); and stamp impression books (1905-1910, 1917).