Tennessee State Route 251 Tennessee State Route 251 State Route 251 (SR 251) is a west–east secondary state highway in Middle Tennessee. SR 251 begins in rural Cheatham County at an intersection with SR 249 (Sams Creek Road/River Road) south of Ashland City. It winds its way southeast along the banks of the Cumberland River as River Road to cross into Davidson County. It continues southeast as River Road Pike as it enters Nashville and has an intersection with US 70/SR 24 (Charlotte Pike), where SR 251 becomes part of Old Hickory Boulevard. It then continues south to have an interchange with I-40 (Exit
Big South Fork of the Cumberland River groups. The first is primarily made up of Ramsey, Hartsells, Grimsley, and Gilpin soils and is located adjacent to the river gorge. The second consists of Hartsells, Lonewood, Ramsey, and Gilpin soils and is found on the nearby plateau. The river draws water from a drainage basin of Carboniferous rock in the Cumberland Plateau. Taken together, the Big South Fork and its tributaries drain between and , of which about 17% is covered by the associated National Recreation Area. The maximum recorded water flow on the Big South Fork was , the minimum recorded was , and the river averages