Duchesne Tunnel: Often overlooked treasure on Mirror Lake Highway drive

   View of the west end of the Duchesne Tunnel. in July, with low water levels. (Photo by Roger Arave.)


By Lynn Arave


WHEN driving along the Mirror Lake Highway (U-150), it is hard not to look upward at the majestic Uinta Mountain Range. However, BELOW ground is a feature just off the highway that most travelers miss ---

 The Duchesne Tunnel is a six-mile long engineering marvel that is a key to providing water to Utah County.
  This tunnel can be viewed at a stop along the Mirror Lake Highway in summer (U-150).
  The stop is signed on both the east and west ends of the highway. However, the west sign is so close to the paved turnout, that motorists may easily pass by and have to turn around and return.
  Watch for it 0.7 of a mile after milepost No. 17, right after the Shady Dell Campground, on the right (south) side of the road for eastbound travelers.
  Although some overgrown trees obscure a good view of it, a 100-foot-long path leads about 40 feet downward to a fenced viewpoint.
  There are also several historical plaques there.
  This concrete-lined tunnel is 9.2-feet in diameter and goes right through a core of the Uinta Mountains, taking water from the north fork of the Duchesne River (a tributary of the Colorado River) to deliver it on the other side of the mountain, to the Provo River watershed.
  Much of the water from this tunnel is stored in Deer Creek Reservoir, for whenever it is needed by the populous southern Wasatch Front.
  It is a horseshoe-shaped rock tunnel.
  Construction on this historic tunnel began in 1948. Work was halted in 1951, when the Korean War began. Work resumed in 1953 and was completed in 1954, meaning it will be 60 years old in 2014.
 Engineers used slide rules and non-electronic equipment to design it. One crew started on the west end and another on the east side -- to meet in the middle.
  When they met, they were only a few inches off each other, -- an amazing feat of accuracy.
  Some claim the tunnel is so straight, you can look through it and see the other end!
  The Provo River Water Users Association manages the tunnel and its construction was part of the Provo River project.
  The tunnel carries the most water in the spring, the least in late summer and early fall.
A special dam, built in 1952, about 21 miles east of Kamas, supplies water for the tunnel. This tunnel slows or stops flows of the north fork of the Duchesne River at a special control gate.

For more information, go to:

http://www.prwua.org/provo-river-project-features/duchesne-tunnel-system/duchesne-tunnel.php