AMP: 205 Location: US-12 and S-500, Musselshell Cty Reassurance shield after the 500 junction. AMP: 220 Location: US-12 and Sumatra Rd, Sumatra, Rosebud Cty A few miles after entering Rosebud County, we’ll approach Sumatra, which is so small it doesn’t even appear on the map, and it’s not like the map is terribly cluttered here. … Continue reading U.S. Route 12, S-500 to I-94 Bus