AMP: 74 Location: US-87 and S-331, Cascade Cty Reassurance shield after the 331 junction. AMP: 71 Location: US-87 and US-89, Cascade Cty A couple miles later, US-89 will split by itself to head south. AMP: 71 Location: US-87 and US-89, Cascade Cty Follow 89 south to Monarch and White Sulphur Springs. AMP: 71 Location: US-87 and US-89, Cascade Cty … Continue reading U.S. Route 89, S-331 to US-87/MT-3/MT-200