The Dave Johnston coal mine, the site of a former 11-mile-long operation, has been returned to its former glory and is now host to some 160 wind turbines.
The mine was determined to be uneconomic by operator Rocky Mountain Power, and reclamation works were undertaken.
Mountains of dirt were moved, miles of land reseeded with native vegetation and major contouring was performed in order to return the landscape to its pre-mining appearance.
More than 80 million metres of earth was moved to accomplish this feat, and the work was completed in 2005.
Sagebrush and other forms of vegetation were planted throughout the property as a source of habitat and food for animals such as prong-horned antelope and deer, and bird nesting habitats were installed for eagles and cover for other, smaller bird species.
And more than 120 "rabbitats," rock shelters for rabbits and other small animals, were built around the property.
Rocky Mountain Power didn't originally set out to convert its property from greenhouse gas-intensive coal generation to green power.
However, it was only after the decision to shut the mine down was made that the utility realised that the location was ideally suited to building a big wind farm because the utility had a significant system of transmission lines already installed nearby and there was a significant wind resource in the barren area.
These days the Glenrock Wind Farm is home to about 1400 antelope and 600 deer mountain lions, foxes, bobcats, rabbits, and golden eagles.
The wind farm could eventually be extended to contain 1000 turbines.
Most former coal land in Wyoming is the first or second phase of clean-up, but the Dave Johnston Mine is notable not only because the final 10-year monitoring phase has closed but because the former non-renewable energy site has become the site of three wind farms.
The three farms — Glenrock, Rolling Hills and Glenrock III — comprise 158 turbines and produce 237 megawatts of power.
These were the first wind projects built on land owned by utility PacifiCorp.
The reclamation efforts secured numerous awards from US federal, state and environmental agencies.
Topping the list is the 2012 Excellence in Surface Coal Mining Reclamation Award for exemplary reclamation accomplishments.
