Question: How long is the river on which Wilbur Dam is located?
Related documents: [0]  [DOC] Wilbur Dam is a hydroelectric dam on the Watauga River in Carter County, in the U.S. state of Tennessee. It is one of two dams on the river owned and operated by the Tennessee Valley Authority. The dam impounds Wilbur Lake, which extends for about 3 mi up the Watauga to the base of Watauga Dam. Completed by 1912 the Ocoee Dam No. 1 is the only Hydroelectric dam that is older, Wilbur Dam was one of the first major hydroelectric projects in Tennessee, and remains one of the oldest dams in the TVA system. [END] 
[1]  [DOC] The Watauga River is a large stream of western North Carolina and East Tennessee. It is 78.5 mi long with its headwaters on the slopes of Grandfather Mountain and Peak Mountain in Watauga County, North Carolina. [END] 
Answer: 
78.5 mi
78.5 mi