When it is full , its surface is at 3,174 to 3,178 feet ( 967.4 to 968.7 m ) above sea level .
Bull Run Lake , the highest lake in the watershed , is natural .
When it is full , Bull Run Lake 's surface is at 3,174 to 3,178 feet ( 967.4 to 968.7 m ) above sea level .
Bull Run Lake , the highest lake in the watershed , is natural .