I am looking for the name of a movie I watched several years ago.  It is similar to Indiana Jones and National Treasure.  I don’t recall who starred in it.  It is about a teenage boy whose dad is gone and I believe his Grandfather is Frank James.  He finds clues that sends him on adventures, he ends up finding the cave where Jesse James hid out which was underground.  He 1st ends up in an old mine with a girl he likes.  His Grandfather thinks Jesse is dead and doesn’t want any part of the search.  They do finally find Jesse alive running a Ranch for troubled kids.  Lots of adventure and funny scenes.  It is set in the late 30’s early 40’s I think. Can someone please help?  thank you