Grand River Dam Authority
10/21/2026 | Press release | Distributed by Public on 10/21/2026 14:14
Completing the Pensacola powerhouse
News
Completing the Pensacola powerhouse
Oct 21, 2026
Prepped for power production … A shot across the generator floor of Pensacola Dam's powerhouse, taken during the early days, before the installation of Units 5 and 6. This week, GRDA revisits those early days with a quick overview of powerhouse history.
It was 86 years ago this week - October 23, 1940 - when the Massman Construction Company out of Kansas City, Missouri officially completed one of the most important contracts tied to the construction of Pensacola Dam.
That contract - Contract 7 - was for the construction of the dam's iconic, art deco-styled powerhouse.
Located on the far west end of the dam, the Pensacola Dam powerhouse houses six hydroelectric turbine-generators, which combine to produce over 120 megawatts of electricity at full generation. The first four of those units were installed during initial construction in 1940. Units 5 (1947) and 6 (1951) would come a few years later, after the dam was returned to GRDA, following the federal government's control during World War II.
However, when those first four units began operation in the fall of 1940, it marked a milestone for Oklahoma, as the state was officially in the hydroelectricity business for the first time ever. In fact, on Saturday, September 28, 1940, a special ceremony was held at the powerhouse to mark the occasion. According to a Tulsa World article detailing the event, GRDA Board Chairman Ray McNaugton "flipped the handle of a small master switch" and, as he did so, it sent over 13,000 volts of electricity into the transformers above the dam.
Just like that, GRDA power - hydroelectric power - was flowing across the system.
The historic Pensacola Dam powerhouse has seen a lot during its 86 years of operations and was even added to the National Register of Historic Places in 2003. Yet, the basic purpose taking place inside its walls - turning the power of flowing water into electricity - remains the same.
Even after all these years of service, the facility remains an important piece of GRDA's overall diverse electric generation portfolio.
GRDA is Oklahoma's largest public power electric utility; fully funded by revenues from electric and water sales instead of taxes. Each day, GRDA strives to be an "Oklahoma agency of excellence" by focusing on the 5 E's: electricity, economic development, environmental stewardship, employees, and efficiency.
Grand River Dam Authority published this content on October 21, 2026, and is solely responsible for the information contained herein. Distributed via Public Technologies (PUBT), unedited and unaltered, on October 21, 2026 at 20:14 UTC. If you believe the information included in the content is inaccurate or outdated and requires editing or removal, please contact us at [email protected]