The river then enters Unicoi County, Tennessee, flowing through ranges of the Bald Mountains and the Unaka Mountains. Turning northwest, the stream is bridged by the Appalachian Trail, and then, just beyond this, by U.S. Highway 19W southwest of Erwin, Tennessee. Near Erwin, two tributary streams, South Indian Creek and North Indian Creek, join the Nolichucky River. Turning more to the north, the stream is paralleled for several miles by State Route 81, crossing into Washington County. The river cuts between several mountains at this point, including Rich Mountain to the south and Buffalo Mountain to the north.
Shortly after entering Washington County, the river makes a horseshoe bend near Embreeville, where it is bridged by Tennessee 81 for the first time. At the northeastern end of Embreeville Mountain, the stream emerges from a large gap, and, turning west-southwest, is bridged by Tennessee 81 again. This region is known as the Ridge and Valley province, underlain primarily by sedimentary rock of the Lower Paleozoic Era. The river then continues west-southwest for several miles, paralleled by State Route 107. The river leaves the roadside near Mt. Carmel. From there it flows northwest over a curving course to Davy Crockett Birthplace State Park near the Washington County–Greene County line. Many tributary creeks join the river in Washington and Greene Counties. At the county line one of the larger tributaries, Big Limestone Creek, joins the river.
From Crockett's birthplace the river flows southwestward, following the trends of the Ridge and Valley province's underlying geology. Bridged by Tennessee 107 just east of Tusculum College, the stream continues southwestward, later bridged by State Route 350 just above an impoundment caused by Nolichucky Dam. This dam was constructed as a hydroelectric project by the former Tennessee Electric Power Company in 1912. The dam was sold to the Tennessee Valley Authority (TVA) in 1939. The TVA continued to operate the dam for electrical power purposes until the 1970s. The degree of siltation of the reservoir, called Davy Crockett Lake, had made continued efforts to operate the facility for hydroelectric purposes impracticable. The agency retired the dam as a power source but continues to maintain it and to use it for flood control and recreational purposes.
The stream then flows almost due west and is then bridged by U.S. Highway 321. Just before the Greene County–Cocke County line the river is bridged by State Route 340. Shortly below this point, the river becomes the Greene County–Cocke County line. A few miles below this point it is bridged by Knob Creek Road, a Cocke County road. Slightly south of Interstate 81, Greene County, Cocke County, and Hamblen County come to a point at a bend in river, where Lick Creek joins the river. From this point on, the meandering stream forms the Hamblen County–Cocke County line.
The confluence of the Nolichucky with the French Broad River occurs in the upstream portion of the Douglas Lake impoundment, caused by Douglas Dam, a World War II-era TVA project. Near the mouth is the Rankin Wildlife Management Area, a reserve operated by the Tennessee Wildlife Resources Agency.
The naturally flowing stream is a popular whitewater rafting and canoeing destination since it has stretches of both white water areas and calm water. Between Poplar, North Carolina, and Unaka Springs, Tennessee, the river gorge provides one of the more scenic and technical whitewater trips in the South.