What are my chances of being able to go to Ft Lewis-McChord or Ft Drum after 12B OSUT?

During OSUT you will get to pick 3 locations and write them down on what’s called a “Wish List”. The Army will take your preferred locations and compare them based on the Army’s needs to decide the duty station for you. You might get one of the ones you chose. It’s pretty much luck of the draw.