The Gauley River rises on Gauley Mountain in western Pocahontas County, and drops nearly 4,000 feet along the 104-mile journey to its juncture with the New River. It meanders southwesterly through Webster County and turns to a more westerly direction through Nicholas County and into Fayette County, where it combines with the New to form the Kanawha River at Gauley Bridge.

The Gauley drains nearly 1,350 square miles, including the watersheds of several large tributaries that flow into it from the south across a wide, fan-shaped region. These are the Cherry, Meadow, Cranberry, Birch, and Williams rivers. The steep-sided walls of the Gauley and its tributaries are lined with massive rock outcrops. The hillsides are intermittently covered with tangles of rhododendron thickets and maturing forests.

Historically, the watershed remained mostly uninhabited due to its difficult terrain. Native Americans hunted in the region, as did the early European explorers. The first settlement of non-Native people was at Peters Creek in Nicholas County at the end of the 1700s. Only a few settlements appeared along Gauley River until the coal and timber barons brought workers in at the end of the 19th century to extract the rich resources.

A Civil War battle took place on the mountain above the juncture of the Meadow River with the Gauley, on September 10, 1861. On that day, Union troops routed a garrison of Confederate soldiers who held a position overlooking the rivers. This was a strategic victory for the Union Army as the ferry located at the tiny hamlet of Carnifex came under Northern control. Carnifex Ferry is now a state park and is listed in the National Register of Historic Places.

Summersville Lake and Dam are located 34 miles above the mouth of Gauley River. The dam was constructed between 1960 and 1966, at a cost of $48 million, to reduce flooding along the heavily populated sections of the Kanawha and Ohio rivers downstream. Though its primary function is flood control, the lake is maintained for intensive recreational use including fishing, motorized boating, skiing, picnicking, sightseeing, hiking, and wildlife enhancement. During the late spring and early summer months, Summersville Lake State Park (established in 2023) provides 2,790 acres of surface water for recreation. During the fall and early winter, the water surface is lowered to allow for storage of spring floodwaters.

A 24-mile section of the Gauley River from the Summersville Dam downstream to the tiny town of Swiss is one of the premier whitewater rafting stretches in the eastern United States. The sport is facilitated by the release of lake water during the months of September and October, when thousands of rafters and kayakers pass through the river's scenic gorge. Due to its scenic beauty and heavy recreation use, 25 miles of the Gauley River and six miles of Meadow River were added to the National Park System as the Gauley River National Recreation Area in 1988.