It depends on which Grand Lake you mean. The most searched Grand Lakes in the United States have different origins. Grand Lake in Colorado is a natural lake formed by natural processes thousands of years ago. Grand Lake o’ the Cherokees in Oklahoma is entirely man-made, created by a dam completed in 1940. And Grand Lake St. Marys in Ohio is also man-made, built in the 1800s as a reservoir for a canal system.
Grand Lake, Colorado: A Natural Lake
Grand Lake in Grand County, Colorado, is the state’s largest and deepest natural body of water. It sits in the headwaters of the Colorado River at an elevation of about 8,369 feet. The lake reaches a maximum depth of 265 feet, covers 515 surface acres, and holds roughly 68,600 acre-feet of water. It was formed naturally, not by any dam or human construction.
That said, Grand Lake’s water management has been altered by human engineering. It sits adjacent to Shadow Mountain Lake, which is a man-made reservoir. Water is pumped between the two as part of the Colorado-Big Thompson Project, a massive system that moves water from the western slope of the Rockies to the eastern side. Shadow Mountain Lake is much shallower, with a maximum depth of only about 36 feet compared to Grand Lake’s 265 feet. So while Grand Lake itself is natural, its water flow and quality have been influenced by the infrastructure around it.
Grand Lake o’ the Cherokees, Oklahoma: Man-Made
Grand Lake in northeastern Oklahoma is completely man-made. The Grand River Dam Authority finished construction of the Pensacola Dam in 1940, and the resulting reservoir became Grand Lake o’ the Cherokees. The lake stretches about 66 miles long with over 1,300 miles of shoreline, making it one of the largest reservoirs in the state. It was built for hydroelectric power, flood control, and water supply. Today it’s one of Oklahoma’s most popular recreation destinations.
Grand Lake St. Marys, Ohio: Also Man-Made
Grand Lake St. Marys in western Ohio is man-made, and it has an interesting construction history. It was built between 1837 and 1845 as a reservoir to supply water for the Miami-Erie Canal, at a cost of about $528,000 at the time. When completed, it was the largest artificially constructed lake in the world. It remains the largest inland lake in Ohio today.
A common misconception is that the lake was dug out of the ground. It wasn’t. According to historical records, the lake was formed by raising two long walls of earth, between 10 and 25 feet high, called the East and West embankments. The eastern embankment stretches about two miles, and the western one runs nearly four miles. These walls, combined with the natural elevation of the surrounding terrain, created a huge basin that filled with water. Dams on Beaver Creek at the west end and Chickasaw Creek at the east end completed the enclosure.
How to Tell Which Grand Lake Someone Means
Context usually makes it clear. If someone mentions Grand Lake near Grove or Monkey Island, they’re talking about the Oklahoma reservoir. If it’s near Celina, Ohio, that’s Grand Lake St. Marys. And if it’s near Rocky Mountain National Park or the town of Grand Lake, Colorado, that’s the natural one. All three are popular for boating, fishing, and lakeside recreation, but only the Colorado lake formed without human intervention.