lighthouses in Alaska
... that due to the isolated locations, keepers at some lighthouses in Alaska were given a year of leave for every four years served?
... that due to the isolated locations, keepers at some <b id="mwBTI"><a href="./List_of_lighthouses_in_Alaska" id="mwBTM" rel="mw:WikiLink" title="List of lighthouses in Alaska">lighthouses in Alaska</a></b> were given a year of leave for every four years served?