Does Indiana Jones have a literary inspiration or equivalent? I am aware of speculation that Indiana Jones is possibly based on one or more hybrids of historical individuals, but does the character have a literary forerunner?

The origins are well documented on Wikipedia.

George Lucas was very public about the character of Indy being inspired by Scrooge McDuck in a treasure hunting storyline, although Alan Quartermain and Professor Challenger are taken to be more direct references.