Blue as a topaz and circled by majestic peaks, this High Sierra gem straddling the California-Nevada border is a bucket-list staple, a place where the air is “very pure and fine...it is the same the angels breathe,” according to author Mark Twain. Lakefront towns dot the shoreline, each with their own appeal. Winter and springtime snow lets you carve it up at world-class alpine resorts. Summer brings out the water toys—sailboats, stand-up paddleboards, kayaks, and almost anything that floats. Fall paints the hills with golden aspen leaves.

Lake Tahoe lays claim to some of the country’s top alpine resorts. On the north shore, Squaw Valley Alpine Meadows and Northstar California are top draws, especially on powder days. On Tahoe’s south shore, Heavenly—one of the world’s biggest ski resorts—offers jaw-dropper lake views from runs as wide and bump free as freeways. Heavenly has also bumped up the fun even if you don’t ski or board, with on-mountain zip lines, tube runs, scenic gondola rides, and a party-like atmosphere on and off the mountain. Tahoe is also home to lower-key resorts—Boreal, Donner Ski Ranch, Homewood, Sierra at Tahoe, Soda Springs, Sugar Bowl, Tahoe Donner. You can also head out on groomed cross-country and snowshoe trails at Royal Gorge or Kirkwood. For a real treat, get your mush on with a sled dog ride near Squaw Valley, Kirkwood, or in Hope Valley, just south of Lake Tahoe.

In summer, many of these same resorts—especially Northstar, Heavenly, and Squaw, offer summertime fun such as mountain biking, hiking, and scenic tram or gondola rides—a great way to get high up in the mountains without a lot of effort.

At this high-desert preserve, on the eastern side of the towering Sierra, ghostlike tufa towers trim the edges of a one-million-year-old lake.

Get a picture of the natural and human history of the Mono Basin at the interpretive center, just off U.S. 395 north of Lee Vining and Tioga Pass (the only route into Yosemite from this side of the mountains). Decks offer dramatic views—Sierra peaks to the west, chaparral-dotted desert to the east—as well as the lake itself and tiny Wizard Island, a nesting site for Western gulls and other sea birds. Bird walks are offered at 8 a.m. Fridays and Sundays, mid-May through Labor Day. The visitor center is closed December through March.

Explore Lee Vining Creek riparian habitat, blanketed with obsidian and pumice, or walk the South Tufa Area for close-up views of the tufa towers formed by the interaction of freshwater springs flowing into the ultra-alkaline lake that’s 2½ times as salty as the ocean. Naturalists lead free walks at the South Tufa Area three times daily from late June through Labor Day. Guided paddles are also offered through Caldera Kayak.

Surrounded by some of the highest peaks in the west, Mammoth Lakes is for serious outdoor lovers, who take to the slopes of signature Mammoth Mountain and nearby June Lake resorts in winter, and when the snow melts, head out to fly-fish in clear mountain streams, hike and mountain bike in high alpine meadows, and dip into natural hot springs.

In winter, Mammoth Mountain, gets, on average, more than 30 feet/9 meters of snow, and is open longer than any resort in the state. Visit the village for shops, restaurants, and nightlife. If you’re not a skier, you can take the gondola to the mountain’s summit at 11,053 feet/3,369 meters for jaw-dropper views of surrounding peaks. Wintry splurges abound—choose from motorized Snowcat tours to guided full-moon snowshoe treks. Go tubing with the kids. Glide through the wilderness on a dogsled. Get a massage at area resorts or dinner at cozy Lakefront Restaurant, surrounded by snowy pines.

California’s eastern Sierras are home to some of the tallest mountains in the country. Among these giants is Mt. Whitney, whose summit scrapes the sky at 14,494 feet/4,418 meters, making it the tallest mountain in the 48 contiguous states, and a popular climbing destination.

People do race up and back in a day (10.7 miles/17.1 kilometers each way), but with awesome views of the Sierra’s tallest peaks and desert plains along the way, there’s no reason to rush. Pitch a tent for the night at Consultation Lake, then tackle the switchbacks leading to the summit. Climbing season is typically May through October, but it can snow at any time, so all climbers should be prepared. Permits, awarded by lottery only, are required.

If reaching the summit isn’t your thing, or you didn’t get a permit, no worries, you can still enjoy the area, with a hike to Lone Pine Lake (roughly 5.5 miles/9 kilometers round trip), including a stay Whitney Portal, a campground in the pines, 13 miles/21 kilometers west of Lone Pine.

The Sierra Nevada Mountains scrape the sky with dozens of peaks higher than 12,000 feet. But the king of them all is Mount Whitney at 14,500 feet, the tallest peak in the 48 contiguous states (although its exact elevation depends on which government agency is measuring—numbers range from 14,494 to 14,508). Bagging the summit requires top-notch physical conditioning plus advance planning to secure a coveted hiking permit (only 160 people are allowed per day). But if peak-climbing isn’t on your agenda, get a taste for this beautiful alpine region by driving up Whitney Portal Road to the trailhead (at elevation 8,300 feet), then hiking to Lone Pine Lake (5.6 miles round-trip). A steady ascent leads through Jeffrey pines and manzanita into the John Muir Wilderness, offering views of Mount Whitney high above and the Owens Valley far below. Picturesque Lone Pine Lake is bounded by sheer granite cliffs, huge boulders, and hardy whitebark pines—a spectacular setting to rest and relax. When you return to your car, stop in at the Whitney Portal Store for mountain-sized pancakes and Mount Whitney souvenirs.

Sequoia National Park’s Ash Mountain entrance, located in the small town of Three Rivers, offers a quick-and-curvy route to the massive sequoias of Giant Forest. Navigate the General Highway’s 130 curves and 12 switchbacks and you’ll be on the fast-track to the General Sherman Tree, the world’s largest living tree by volume. Once there, get out and walk—it’s the only way to fathom the sequoias’ sheer size and regal beauty. Salute the General Sherman, then move on to the quieter Congress Trail, where hundreds more gargantuan trees grow. After you’ve been thoroughly astonished by these ancient giants, take a heart-pumping climb up Moro Rock’s 360 stairsteps. Even young kids can make it to the top of this bald granite precipice with a sweeping vista of the saw-toothed Great Western Divide. For dinner, head to the park’s Wuksachi Lodge. In The Peaks’ glass-walled dining room, every table overlooks a forest of firs and the Silliman Crest.

Coming from the east, Yosemite unfolds with high-country beauty, a land of granite crags and alpine meadows, the best known being Tuolumne Meadows, with well marked trails endless scenery. From its tranquil edges, hiking trails lead in all directions—to the alpine lakes set below the spires of Cathedral and Unicorn Peaks, to a series of roaring waterfalls on the Tuolumne River. The meadow’s small visitor center, housed in a historic cabin, features exhibits that focus on the area's geology, wildflowers, and wildlife.  Continuing west you reach the park’s signature site, Yosemite Valley, where shuttle buses can take you to all the key sites.

California’s first national park and designated as a UNESCO World Heritage site in 1984, Yosemite attracts 4 million visitors each year—with good reason. Nearly the size of Rhode Island and covering more than 1,100 square miles/284,899 hectares, it features unforgettable natural beauty. Among Yosemite’s many bragging rights, its waterfalls rank high. In the list of the world’s 20 tallest waterfalls, Yosemite Valley scores three spots for Yosemite Falls, Sentinel Fall, and Ribbon Fall. Yosemite Falls holds the undisputed title of the tallest waterfall in North America. It’s a challenging hike to the top of the 2,425-foot/729-meter falls, but fortunately it’s an impressive view from the base to—an easy and scenic 1-mile/1.6-km loop that should be on everyone’s bucket list. An easy walk to 620-foot/189-meter Bridalveil Falls takes you to an overlook point below its billowing cascade. A more demanding hike to Vernal and Nevada Falls ascends granite steps to the brink of two massive drops, where you can watch the entire Merced River plunge over the rocky ledge. (Adhere to all safety signs and stay behind all ropes and signs.)

From Yosemite, continue south on the west side of the Sierra, following roads that dip down to the fertile Central Valley, to your last stop at a twin park that protects the world’s largest living things and a wild and rugged alpine canyon.