My DH and I are visiting Lake Tahoe and went hiking up to Horseshoe Falls, just west of South Lake Tahoe. It's an arduous hike from the point of view of a less athletic person like me. But I didn't trip over the numerous branches, rocks, and roots that tried to lay me out, and I got to the base of the falls in one piece. Good thing, because I was overcome by all the scenery and the thunderous water roaring downhill. So I got out my knitting project and relaxed for a half hour while DH climbed farther up to near the top.
The only place as breathtaking as this in my experience is Zion National Park in Arizona (or is it Utah??).
Anyone who has never been in the Sierras has to come to Tahoe once in your life!