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
Maryland Route 51 state highway reduces to a two-lane road after passing Uhl Highway, an old alignment of MD 51 that is unsigned MD 51E. The rail yard ends at Mexico Farms Road, which provides access to Mexico Farms Airport and the Warrior Run Generating Station. Within the hamlet of North Branch, MD 51 intersects as other end of Uhl Highway as well as Pittsburgh Plate Glass Road, which serves the North Branch Industrial Complex, including Federal Correctional Institution, Cumberland. MD 51 enters a rural area and parallels the C&O Canal southeast through Spring Gap. The state highway turns away from the Potomac