Here is a link to CalTrans camera of the old and new donner pass route, the old curvy one is in the foreground and is generally used eastward (downhill to the left) while the new main is higher to the rear and is used mainly westward (up hill). Both tracks could be located on the new ROW but UP is too cheap to make up for Mr. Russel's (SP) scrapping tracks.
Jobst Brandt