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
Arizona State Route 51 occupancy vehicle lane in each direction and on ramps to Loop 101 eastbound. Work was completed in the summer of 2008. In March 2016, a new interchange from the road's existing terminus at Loop 101 to an intersection with Black Mountain Boulevard opened. Arizona State Route 51 Arizona State Route 51 (SR 51), also known as the Piestewa Freeway, is a numbered state highway in Phoenix, Arizona. It connects Interstate 10 just outside Downtown Phoenix with Loop 101 on the north side of Phoenix, making it one of the area's major freeways. It is a largely north–south route and is