History of the Grand River and Pensacola Dam

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The Grand River - from

"A History of the Grand River Dam Authority"

by W.R. Holway

Grand River is formed by the junction of the Neosho and Spring Rivers some ten miles southeast of the city of Miami, Oklahoma.

It flows in a southerly and southwesterly direction about 125 miles to empty into the Arkansas River five miles northeast of the city of Muskogee. The river is entirely within the boundaries of the state of Oklahoma and receives the drainage of the tributaries on the western slopes of the Ozark Mountains.

It has a fairly constant low-water flow of considerable volume, due to its many spring-fed tributaries and, in times of flood, carries a large volume of water. The river channel has a good width and well-defined banks, changing little with the years. The valley floor is narrow, rarely exceeding two miles in width and, in many places, is scarcely a mile wide, with hills on both sides of the valley. The stream has a fall of two feet per mile and is adapted to development of water storage reservoirs and hydroelectric plants.

History of Pensacola Dam

By GRDA Media Department

Located in the heart of Northeast Oklahoma’s Green Country, Pensacola Dam and Grand Lake O’ the Cherokees provide flood control for the Grand River and produce hydroelectric power for Grand River Dam Authority. Known as the Grand River Project, the facility was the first hydroelectric system in Oklahoma.

It started as one man’s dream. In the late 1800’s, Henry C. Holderman first envisioned building a dam on the Grand River to bring electric power to the Cherokee Nation in Indian Territory. In an effort to make his dream a reality, Holderman, his brother Bert and two student engineers from Spaulding Institute in Muskogee traveled down the river in a crude, homemade houseboat to complete the first engineering survey.

Holderman worked for years to acquire financing for the project and came close on a couple of occasions. While Holderman watched, a group of men known as the “Rainbow Chasers” turned the dream into a reality. These men, including Jack Rorschach and George Schaefer of Vinita, and Clay Babb and Owen Butler of Grove, made several trips to Washington, D.C., to secure funding for the Pensacola Dam. With the help of Representative Wesley E. Disney and W.R. Holway, funding was approved by President Franklin D. Roosevelt on September 18, 1937.

Following President Roosevelt’s approval of funds, Holway and Neuffer, engineers for the project, began survey and engineering work on October 25, 1937. Massman Construction Company of Kansas City, Missouri, was selected as the major contractor for the dam and powerhouse.

After six months of preparation, Massman began pouring the first of 510,000 cubic yards of concrete on December 30, 1938. The 24-hour-a-day continuous pour was completed 20 months later. The final openings in the dam under arches seven and eight were closed on March 21, 1940. The lake was full by the end of that summer.

Governor Leon Chase Phillips opened the road across the dam on August 13, 1940. The entire contract on the dam was completed on October 4, 1940. Twenty-one months and 4 days after it began.

Pensacola Dam is the longest multiple arch dam in the world, spanning approximately one mile. The structure’s 51 arches and 21 spillways combine for total length of 5,145 feet. Each arch has a clear span of 60 feet.

Water through each of the spillways is controlled by flood gates measuring 25 feet by 36 feet. These gates are operated by two 60-ton hoists. The dam towers as much as 150 feet above the riverbed.

Engineers chose a multiple-arch design for the Pensacola Dam because materials were scarce and, therefore, expensive in the late 30’s. This type of construction required a great deal of manpower, but in the days of the Great Depression, manpower was an abundant resource. Due to the hard times of the Depression, thousands flocked to the proposed construction site long before work ever began, hoping for employment. Approximately 3,000 men worked on the project. “Common” or “blue collar” laborers earned about $16 per week.

In order to begin construction, 1.6 million cubic yards of earth and rock were excavated. Building the dam required nearly 23.9 million pounds of reinforcing and structural steel and 625,000 barrels of cement to make 510,000 cubic yards of concrete.

Before the dam was built, people believed the power produced there would be more than GRDA could ever market. Today, GRDA’s five generating facilities have a generating capacity of 1,480,000 kilowatts, fifteen times the generating capacity of the Pensacola Dam. Operated by GRDA, the dam’s powerhouse contains six hydroelectric generating units with a total generation capacity of 96,000 kilowatts.

Grand Lake O’ the Cherokees is one of the most popular tourist attractions in Oklahoma. The 43,500-acre lake has about 1,300 miles of shoreline, more than any other lake in the state. Its wooded coves and rolling hills have made it one of the most desirable retirement areas in the United States. Different than most lakes, private ownership of land extends to the water’s edge. Visitors and residents alike enjoy a variety of activities on Grand Lake, including boating, bass fishing, swimming, scuba diving, jet skiing and water skiing.

Created in 1935 by the fifteenth Oklahoma Legislature, the Grand River Dam Authority was established as a “conservation and reclamation district.” GRDA is Northeast Oklahoma’s public power supplier. While an agency of the State of Oklahoma, the Authority is self-supporting, funded primarily by electric revenues rather than by taxes.

In addition to the Pensacola Dam, GRDA generates hydroelectric power at the Robert S. Kerr Dam, and the Salina Pumped Storage Project and produces power with two thermal generation units at the Coal-Fired Complex near Chouteau, Oklahoma.