From Ancestry.com Wiki
This entry was originally written by Dwight A. Radford in Red Book: American State, County, and Town Sources.
Residents of Alaska became U.S. citizens when the area was purchased from Russia in 1867. Naturalization and citizenship records for those arriving after that time were filed in the judicial districts. These are also on file at the Alaska State Archives and the FHL, and they include old territorial records of Fairbanks, Juneau, and Nome that have been transferred to the superior court. The National Archives—Pacific Alaska Region has many citizenship records for Alaska. These include declaration of intention (1900–29) and special court orders (1914–32) for Juneau; declaration of intention (1901–17) for Skagway; petition case files (1910–14) for Fairbanks; and petition case files (1910–20) for Iditarod.