Exploring mysterious Pyramid Lake and its odd tufas

When explorer John C. Fremont first set eyes on Pyramid Lake, he was impressed.

"We encamped on the shore, opposite a very remarkable rock in the lake, which had attracted our attention for many miles," he wrote in his journal in 1843. "It rose, according to our estimate, six hundred feet above the water; and, from the point we viewed it, presented a pretty exact outline of the great pyramid of Cheops."

It seems appropriate that, as an explorer, Fremont was filled with thoughts of ancient Egypt when he first encountered Pyramid Lake because, like the great pyramids, it has a timeless and mysterious quality.

Part of the lake's uniqueness lies in the stark contrast between its blue waters and the surrounding brown desert. Pyramid is the largest remnant of ancient Lake Lahontan, a giant inland sea that once covered most of Nevada.

The lake, about 45 miles north of Reno, receives a regular flow of water from the Truckee River, which begins at Lake Tahoe. It is also the center of the 322,000-acre Pyramid Lake Paiute Reservation.

When Fremont stumbled upon the lake, he found it teeming with large fish, noting that "their flavor was excellent - superior, in fact, to that of any fish I have ever known."

Over the years, the fish have remained important to the lake and its people. Anglers have long sought Lahontan cutthroat trout at Pyramid. The world record for a cutthroat trout - 41 pounds - was established there in 1925.

The lake is also famous as home of the rare cui-ui, a fish that first appeared more than 2 million years ago. Today, the fish is an endangered species protected by the U.S. government.

Pyramid Lake makes an enjoyable day trip. It is a fine spot for picnicking, camping, boating, water-skiing, swimming, hiking, exploring or just driving around.

The lake's shores are dotted with many interesting tufa formations. The pyramid is made of this pitted stone that is formed when natural springs filled with calcium mineral water leak into salty, carbonate water. A chemical bonding occurs, which results in the creation of a limestone-like substance known as tufa.

Formations such as those found around Pyramid Lake are the result of a build-up of tufa material, which can only occur under water. However, once water recedes and the tufa is exposed to air, it ceases to grow.

Pyramid Lake is also the site of considerable geothermal activity. In several places around the lake, including cracks in the pyramid, boiling hot water pours from natural underground hot springs.

At the lake's north end, which is not open to the public, steam can be seen escaping from holes and cracks along the shore (you can see it while boating on the lake).

At several places along the shore, you can also find other unusual tufa formations. For instance, nearly adjacent to the pyramid are several giant tufa bubbles, which are mushroom-shaped rocks that are hollow in the middle.

One of the most famous of Pyramid's formations is "Great Stone Mother and Basket," a remarkable tufa formation that resembles a seated Indian woman with an open basket next to her.

One of the legends about the Stone Mother is that she was so filled with remorse when some of her good children were driven away by evil siblings that she began to cry, filling the lake with her tears. Her basket remains empty, awaiting the children's return.

Another of Pyramid Lake's more unique features is Anaho Island, near the lake's east shore. The 247-acre island is a national wildlife refuge that serves as a sanctuary for colonial nesting birds, primarily American white pelicans.

The island is off limits to people, but home to dozens of birds in addition to the pelicans, including cormorants, California gulls, great blue herons and snowy egrets.

The Pyramid Lake Museum and Visitor Center contains exhibits describing the tribe's history and culture, as well as the lake's natural history. Here, you can also purchase camping, boating and fishing permits, which are required at the lake.

For information about Pyramid Lake, contact the Pyramid Lake Museum and Visitor Center at (775) 574-1088.

• Richard Moreno is the author of "Backyard Travels in Northern Nevada" and "The Roadside History of Nevada."