AMP: 12 Location: S-427 and US-87, Judith Basin Cty Reassurance shield as S-427 begins. AMP: 0 Location: S-427 and US-89, Cascade Cty 12 miles later, we’ll approach US-89. AMP: 0 Location: S-427 and US-89, Cascade Cty Turn left for US-89 south and right for US-89 north.  S to S-259, N to US-87/MT-3/MT-200  S to S-551, N to US-89 … Continue reading Montana Secondary Highway 427, US-87/MT-3/MT-200 to US-89