[Answer] Visitors to Longhorn Cavern State Park outside Austin will learn that outlaw Sam Bass is said to have hid something inside the cavern. What was it?

Step 1 : Introduction to the question " Visitors to Longhorn Cavern State Park outside Austin will learn that outlaw Sam Bass is said to have hid something inside the cavern. What was it? "

...1. a trunk of jewelry 2. $2 million 3. his taxidermied cat 4. a treasure map to booty from the Great Train Robbery