Few forget their first glimpse of Crater Lake on a clear summer’s day—21 square miles of water so intensely blue it looks like ink, ringed by cliffs towering up to 2,000 feet above. The mountain bluebird, Native American legend says, was gray before dipping into these waters. The tranquil gem of the Cascade Range is set in a dormant volcano called Mount Mazama, one in the chain of volcanoes that includes Mount St. Helens. Mount Mazama’s eruption about 5700 B.C. catapulted volcanic ash miles into the sky and expelled so much pumice and ash that the summit soon collapsed, creating a huge, smoldering caldera. Eventually, rain and snowmelt accumulated in the caldera, forming a lake more than 1,900 feet deep, the deepest in the United States. Wildflowers, along with hemlock, fir, and pine, recolonized surroundings. Black bears, bobcats, deer, marmots, eagles, and hawks returned. Lava outcrops jut from the northwest rim of Crater Lake. Lava outcrops jut from the northwest rim of Crater Lake. Visitors can find several overlooks along Rim Drive, which circles the water. PHOTOGRAPH BY DAVID MCLAIN, NAT GEO IMAGE COLLECTION Scientists have yet to completely understand Crater Lake’s ecology. In 1988 and 1989, using a manned submarine, they discovered evidence that proves hydrothermal venting exists on the lake’s bottom and may play a role in its character. Crater Lake forms a superb setting for day hikes. Thanks to some of the cleanest air in the nation, you can see more than a hundred miles from points along many of the park’s 90 miles of trails. Forests of mountain hemlock and Shasta red fir predominate near the caldera rim, where twisted whitebark pines testify to the harshness of the long winter. Ponderosa pine, the park’s largest tree, and lodgepole pine are common farther down from the rim. Can’t-miss experiences The road linking two small villages—Mazama and Rim—and service centers on the south side of the park provides some of the best scenery away from the lake itself. The seven miles from Mazama to Rim exposes visitors to the region’s dry pine forest ecology, with some wonderful wildflower meadows. While in Rim Village, stroll to Sinnott Memorial Overlook to gaze at the lake’s turquoise waters. Spend at least a half day touring the 33-mile Rim Drive, enjoying its many overlooks and several hiking trails. From the southeast portion of Rim Drive, take Pinnacles Road about six miles to see the Pinnacles, an unusual grouping of volcanic pumice spires. As the sides of Wheeler Canyon eroded away, these graceful fossil fumaroles emerged, each marking where volcanic gas rose up through hot ash deposits. There’s an overlook from the parking area, on an easy half-mile trail. A volcano inside a volcano, Wizard Island rises above Crater Lake in this archival photo from July, 1962 A volcano inside a volcano, Wizard Island rises 767 feet above the surface of Crater Lake, in this archival photo from July of 1962. PHOTOGRAPH BY WALTER MEAYERS EDWARDS, NAT GEO IMAGE COLLECTION Perhaps the best secret hike in the park is across the lake—the Watchman Trail, which interpretive ranger Dave Grimes says “offers the best of the park in one trail.” It is only moderately steep, climbing just 420 feet in 0.8 mile (one way). To experience the lake itself, hike down the mile-long Cleetwood Trail to the dock on the shore. From here, a concessioner offers boat tours that circumnavigate the lake in two hours, while providing fine lessons on the geology and history of Crater Lake. The tour comes with great views of the only islands in the lake, Phantom Ship (so named because it seems to disappear completely against the crater’s walls when viewed from much of the rim) and the cinder-cone peak of Wizard Island. The standard tour runs often during peak season, typically July through September. On a second day, consider exploring more of Wizard Island. From the island dock, a mile-long trail weaves upward through a series of switchbacks to the crater at the cinder cone’s summit at 6,940 feet. The rim of this crater-within-crater provides views of the lake that only a tiny fraction of visitors ever get to see.