(Historic Photo: September 2009) AMP: 38 Location: S-451 at the Wyoming Line, Big Horn Cty Reassurance shield as 451 begins. 451 follows old US 87 up to Garryowen AMP: 34 Location: S-451 and Aberdeen Rd, Big Horn Cty A couple miles later, we’ll approach a county connector to I-90. Turn right to head over there. AMP: 28 Location: S-451 … Continue reading Montana Secondary Highway 451, WY-345/WY State Line to MT-457