Ames, Colorado: Where Alternating Current Proved Edison Wrong

Ames, Colorado is a tiny unincorporated community in San Miguel County at 8,720 feet elevation, about twenty minutes' drive south of Telluride. The Ames Hydroelectric Plant still operates today, now run by Xcel Energy, but the mining community it powered has vanished.

01Why Was Ames Founded?

The Ames Hydroelectric Generating Plant was the brainchild of Lucien L. Nunn, a lawyer from Telluride. Nunn had invested in the Gold King Mine at Alta, 11,800 feet up in the mountains. The mine's steam-powered operations were ruinously expensive — hauling coal to nearly 12,000 feet was consuming most of the mine's profits.

Nunn approached George Westinghouse, who was then developing Nikola Tesla's alternating current technology. Tesla had patented his AC motor in 1888. Westinghouse was manufacturing the equipment. What they needed was a customer willing to bet a mine on untested technology.

Nunn was that customer.

02The World's First Commercial AC Plant

Westinghouse Electric and Manufacturing Company supplied a Tesla motor and generator for the Ames plant. The station, built on a fork of the San Miguel River, generated 3-kV single-phase power and transmitted it approximately 3 miles uphill to the ore crusher at the Gold King Mine.

The Ames plant began operation in mid-1891. It worked. The Gold King Mine's electricity costs collapsed. The proof of concept demonstrated that alternating current could be generated at one location, transmitted long distances through wire, and delivered at useful power levels to an industrial operation miles away.

This was the moment the Edison-Tesla "War of Currents" tilted decisively toward AC. Edison's direct current system could not transmit power more than a mile or two without unacceptable losses. Tesla's AC system, proven at Ames, could.

03Engineering Significance

The Institute of Electrical and Electronics Engineers (IEEE) recognizes the Ames plant as the world's first commercial AC power station. The Library of Congress has HABS (Historic American Buildings Survey) documentation of the plant. The Edison Tech Center in Schenectady, New York maintains a detailed account of the Telluride/Ames power system.

The plant's success at Ames led directly to the construction of the Niagara Falls AC power plant in 1895 — the project that brought Tesla's system to the eastern United States and ended the DC era.

04Can You Visit Ames Today?

Yes. Drive south from Telluride on Colorado Highway 145 toward Ophir. The Ames Hydroelectric Plant is visible from the road. TripAdvisor lists it as a local attraction. Visitors interested in electrical history will find it rewarding — a small, unassuming building on a mountain river that changed the world's energy infrastructure.

05What Remains of Ames Today

The Ames Hydroelectric Plant still operates. It has been upgraded with two Pelton turbines and a 3.6-MW generator, but sits on the same site, using the same water source, that powered the world's first commercial AC transmission in 1891. Xcel Energy runs the facility.

The Illium Valley surrounding Ames is quiet. A few residences sit along the road. The Gold King Mine at Alta, which the plant was built to serve, has been closed since 1948. But the power plant — Tesla's proof of concept — is still running after 135 years.