Blue as a topaz and circled by majestic peaks, this High Sierra gem straddling the California-Nevada border is a bucket-list essential. Lakefront towns dot the shoreline, each with their own appeal. Winter and springtime snow let 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. But no matter what the season, this is the kind of place that makes you plan the next trip back before you even leave.