California and Nevada converge at border-straddling Lake Tahoe, the largest alpine lake in North America. More than a dozen ski resorts line its shores, and 24-hour casinos bring nonstop Vegas-style bling. In summer, the clear water bustles with jet skis, kayaks and scenic boat tours, and the Sierra Nevada trails fill with hikers. Stay on the south side of the lake for nightlife and activities within walking distance; head to the north shore, site of most ski resorts, if nature takes priority.