AMP: 93 Location: 10th Ave S and 15th St S, Great Falls Reassurance shield as US-87 joins the concurrency. AMP: 92 Location: 10th Ave S and 43rd St S, Great Falls Reassurance shield several blocks later. AMP: 91 Location: 10th Ave S and 57th St S, Great Falls Reassurance shield as we start to head out of Great … Continue reading U.S. Route 89, US-87 to S-227/S-228