AMP: 0 Location: Black Mountain Rd and US-20, Hot Springs Cty Reassurance shield at the beginning of WYO 172, an 11 mile spur to nowhere AMP: 11 Location: WYO 172 and Black Mountain Rd, Hot Springs Cty WYO 172 ends, as does the pavement, and Black Mountain Rd continues. E to WYO 120, W to … Continue reading Wyoming Highway 172, US-20/WYO 789 to Black Mountain Rd