Idaho State Highway 51 Idaho State Highway 51 State Highway 51 (SH-51) is a state highway in southwestern Idaho from Mountain Home south to the Nevada border, where it continues as State Route 225 to Elko. It is the major north–south road in Owyhee County. As currently configured in the state's official milepoint log, SH-51 terminates at the BL-84 intersection with American Legion Blvd., and is not otherwise officially concurrent/overlaid with BL-84 (where the signs at I-84's Exits 90 and 99 say "To SH-51/To SH-67") or the former section of US-20 that follows American Legion Blvd. to I-84/US-20 east at Exit 95. As of
Minnesota State Highway 51 Highway 51 parallels State Highway 280 through Falcon Heights and the Midway neighborhood of Saint Paul. State Highway 51 was authorized in 1933. The route was paved by 1935. The original alignment on the south end of Highway 51 was from West 7th Street up Edgecumbe Road to Snelling Avenue. This section of Highway 51 was later rerouted to Montreal Avenue. From 1934 to 1935, the north end of Highway 51 previously followed Snelling Avenue northbound to County Road B in Roseville, then 51 turned westbound to Fairview Avenue and ran northbound along Fairview Avenue and New Brighton Road to