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PVREA Project

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Nucla Sunshine Project

Wayne Child





Nucla to Sunshine 115 kV transmission line project


Southwest Colorado transmissionThe town of Telluride in southwest Colorado is tucked back in the San Miguel River canyon, surrounded by steep forested mountains and cliffs.  The former silver mining town is now a bolstering ski resort community.  Telluride is served by Tri-State member system San Miguel Power Association (SMPA) based in Nucla. 


The region’s primary source of power is a 92-mile, 115 kilovolt (kV) transmission line operated by Tri-State that originates at the Hesperus Substation near Durango and traverses over Coal Bank, Molas and Ophir Passes.  It is vulnerable to avalanche and forest fires, and if the line experiences an outage, reduced power and rolling blackouts will occur.


A secondary power source is a 69 kV line from Nucla owned by SMPA that feeds the area and was originally constructed in 1948.  The 50-year-old line is at the end of its useful life, is vulnerable to lightning strikes and is costly to maintain.  Additionally, this line cannot support the electric load during peak energy usage times in the Telluride area if the line's primary source from Durango goes out.



Construction begins June 1, 2010


Nucla-Sunshine construction timeline



Tri-State’s Nucla – Sunshine 115 kV transmission project will replace the existing 69 kV line.  Per Federal Energy Regulatory Commission regulations, Tri-State will own and operate the line as it is a transmission operator.  The old line will be removed and a new line will be constructed, following some of the original alignment.


Tri-State received permission to proceed from San Miguel County, Montrose County, the Bureau of Land Management and U.S. Forest Service once the cooperating agencies approve the Construction, Operation and Maintenance Plan.


The new line will start at the Nucla Substation, west of Naturita and will terminate at the Sunshine Substation near Telluride.   The Nucla-Sunshine Project encompasses approximately 50 miles of new line and transmission facilities, including:



  • Constructing a new 19.9-mile-long, 115 kV line from the Nucla Substation to the Norwood Substation, across portions of Montrose and San Miguel counties.
  • Constructing a new 30.4-mile-long, 115 kV transmission line from the Norwood Substation to the Sunshine Substation near Mountain Village on Ilium Road (aka South Fork Road), consisting of 20.4 miles of overhead line and 10 miles of underground line (across portions of Specie and Wilson mesas in San Miguel County).
  • Expanding the Norwood Substation, near the town of Norwood on two acres of private land.
  • Replace the existing Wilson Mesa Substation in San Miguel County.
  • Modifying the existing Nucla and Sunshine substations.
  • SMPA will remove the Oak Hill Substation on Wrights Mesa and Specie Mesa Substation, reclaiming the property to its original state.


Project Map




Contact Information


Sarah Carlisle

Public Affairs Coordinator


Updated: June 1, 2011


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