Renewable Energy Contractor and Developer Construct Wind Project in California

MINNEAPOLIS, MN (November 7, 2011) - Mortenson Construction, a leading North

American renewable energy contractor, was recently selected by San
Diego-based developer enXco, an EDF Energies Nouvelles Company for the
construction of the Pacific Wind Project. Located on the south slope of the
Tehachapi Mountains in Kern County California, the 8,500 acres project will
generate140 megawatts of wind power - enough energy to power approximately
39,000 homes.

Mortenson is responsible for the design and construction of access roads,
foundations, erection, overhead and underground electrical collection
system, and a 14,400-square-foot O&M facility that will support the Pacific
Wind Project as well as other enXco projects slated for development in the
area. Construction will begin in December, 2011 and is expected to be complete in August, 2012.

The Pacific Wind Project is the 19th wind power facility that Mortenson has
constructed in partnership with enXco. Together the partnership has provided
nearly 2 GW of energy throughout the United States. In early October,
Mortenson completed construction of enXco's 205.5 megawatt Lakefield Wind
Project in southern Minnesota. In Minnesota alone, the enXco - Mortenson
partnership has developed and constructed approximately 36 percent of the
state's wind energy capacity.

"Our long-established relationship with enXco represents a cohesive
partnership that reinforces our commitment to renewable energy though out
the United States," said Tim Maag, a vice president and general manager of
Mortenson's Renewable Energy Groups.

Since entering the renewable energy market in 1995, Mortenson Construction
has become a leading builder of wind power facilities in North America,
constructing more than 100 wind projects generating more than 11,000
megawatts of renewable power across the United States and Canada. With 100
percent of Mortenson's business in the power sector coming from renewable
energy, Engineering News-Record ranked Mortenson the 11th largest power
contractor in the U.S. for 2010. In addition to wind power, Mortenson's
Renewable Energy Groups, also construct facilities that generate solar
power, biofuels and hydro-electric power.

About Mortenson Construction

Founded in 1954, Mortenson Construction is a U.S.-based, family-owned
construction company. Ranked as the 19th largest contractor in America,
according to Engineering News-Record, Mortenson provides a complete range of
services, including planning, program management, preconstruction, general
contracting, construction management, design-build, and turn-key
development. Mortenson has offices in Chicago, Denver, Milwaukee,
Minneapolis, Phoenix, and Seattle with international operations in Canada
and China. For more information, please visit www.mortenson.com/wind.