Lake Tahoe

Looking eastward from the summit of Ellis Peak (8740 ft/2664 m). The mountains on the skyline, the Carson Range, are in Nevada. Ellis Peak has a well-defined trail which, alas, is open to motorbikes as well.
Lake Tahoe is natural, altho its level was raised in the early years of the last century by a small outlet dam, for water storage. It's the 6th largest lake by volume in the US, after the 5 Great Lakes. Its maximum depth is 1645 ft (501 m), second-deepest in the US after Oregon's Crater Lake. It's the largest alpine lake in North America, meaning its elevation is >5000 ft (1524 m). For historical reasons, the Californa-Nevada state line is out in the lake, and indeed the turning point on the boundary, where it shifts from north-south to southeasterly, is out in the middle of the lake(!)