Ok, if the numbers on this image are "2291" I am convinced that at least this course was from Hilo to Oakland, which is 2292 miles according to Google Earth.
Ok, Googling for Earhart and Hilo..."And though you may not be able to visit Earhart's final resting place, the banyan tree that she planted in Hilo on Jan. 6, 1935, now towering above Banyan Drive, is marked with a plaque. On O'ahu, a roadside lookout on Diamond Head Road in Kuilei Cliffs Beach Park also has a plaque commemorating Earhart, in honor of that first solo flight from Hawai'i to the Mainland. It's a fitting place to stop, gaze out to sea and remember the courage of the woman who crossed it alone."http://www.sfgate.com/cgi-bin/article.cgi?f=/g/a/2010/07/23/alohafriday072310.DTLSeriously?
According to this, Honolulu was the final destination:http://tighar.org/Projects/Earhart/Archives/MapsandPhotos/maps/worldflight.html
Does the name Percival Lowell ring a bell?