The highway along this entire route is unpaved and has 35 one-lane tunnels before it emerges onto the western face of the Cordillera Negra high above the town of Huallanca.
The river from this same bridge goes generally northward through the Cañón itself and eventually its water powers the turbines of the hydro electricity plant at Huallanca.
At approximately the same latitude as that of highway tunnel 18 the nearby (eastward) river's natural banks are as close as 6m apart; the crests of the two cordilleras loom above, at places as high as 6000m above sea level.
A short distance north (downstream) of this constriction in the Cañón is a diversion dam that deflects measured amounts of the river's water into a man-made tunnel.
The powerplant is entirely within a huge manmade cavity a hundred meters inside the rock of the mountain on the east edge of Huallanca.