AMP: 162 Location: US-12 and S-381, Musselshell Cty Reassurance shield after the 381 junction. AMP: 167 Location: US-12 and US-87, Musselshell Cty A few miles later, we’ll approach US-87 AMP: 167 Location: US-12 and US-87, Musselshell Cty Follow 87 south to Billings. Stay on 12 east and 87 north to head into Roundup. AMP: 167 … Continue reading U.S. Route 12, S-381 to US-87