Ah, the vibrant blue water of Lake Tahoe. Mark Twain wrote of this "noble" blueness; Scientists are studying it; NASA is monitoring the water with a thermometer and radiometer every two minutes.

This brilliant freshwater lake straddles Nevada and California, offering up 72 miles of shoreline year round with glistening water, framed by alpine-covered mountains. Nearby skiing, dining, lodging and backcountry make this a world-class destination.

Note: Do not adjust your computer monitors. Blueness of lake in map above does not reflect actual blueness of Lake Tahoe.

True blue

The blue water of Lake Tahoe's many great beaches, like Sand Harbor (pictured above and below) attract beach bums and sun worshipers from around the world for a myriad of water activities like swimming, sun bathing, boating, fishing, scuba diving and parasailing. Lake Tahoe is the largest alpine lake in the United States, and the wilderness around it is perfect for hiking. You may even stumble upon a waterfall or wildlife so don't forget your camera.

When it comes to the lake's water, there's no denying the blueness or the clarity. It's like a 12-mile by 22-mile heavenly dream beckoning you to skip a rock, dip your toes ... or dive in. Are you tempted?

How about now?

Now?

The lake is even more picture perfect in the winter. Snow-capped mountains as a backdrop for ultramarine water; water that never freezes. Did life suddenly transform into a postcard?

It's not easy being blue

While the sparkling blue water of Lake Tahoe is indeed both blue and clear, these two things aren’t entirely related. Its blueness actually comes from its low levels of algae not its clarity, a fact discovered by scientists at U.C. Davis and printed in their annual State of the Lake.

The measurements NASA is taking, meanwhile, are related to a satellite measuring the earth for an environmental study. Lake Tahoe was chosen as a measuring location in part because of its clarity as well as its proximity to U.C. Davis.

"Keep Tahoe Blue"

Lake Tahoe’s clarity decreases every year for a variety of reasons, both natural and man made. Yes, the clarity and the blueness are separate, but the factors related to the decreasing clarity also impact the blueness. Fortunately, this has not gone unnoticed.

If you live in or have visited the Tahoe area you've likely heard the motto "Keep Tahoe Blue." You can see it on bumper stickers, hats, shirts and shot glasses. There's even a "Keep Tahoe Blue" baby onesie (#fashionpriorities). The motto comes from the League to Save Lake Tahoe, an environmental watchdog group that serves to encourage enjoyment of the lake while also protecting and restoring it.

Just looking at the water of Lake Tahoe, like at Bonsai Point above, and it's hard to argue against keeping this gorgeous lake blue.

If you enjoyed reading about the blue water of Lake Tahoe you may also enjoy, 8 Natural Swimming Spots With The Clearest, Most Pristine Water In Nevada.