Hiked (we call it backpacking) the Yosemite trail that takes you from the valley floor all the way up behind Half Dome. Camped overnight (rough) and came back the next day. Coming down was harder that going up due to the pounding of the knee joints. Don't recall the distance but the elevation change was a killer. Steep!
Another time I hiked up into the mountains above the Hetch Hetchy dam to a lake that was at 10,000 ft. Got a miserable altitude headache but we caught native trout (YUMM), slept under the most vived Milky Way I have ever seen and had a great time.
We now live on the Pacific Crest Trail (Cascade Locks, OR.) and I talk with hikers every year who come into town to pick up their relay provisions at the post office. Most are coming from the south end (Mexico) and are heading for the Canadian terminus. They are kids in their twenties who look about 40! We can leave the house and walk up the mountain to the trail and walk it for a couple of miles to some breathtaking waterfalls and come back home in time for dinner. We have scared off bears from the blackberries a couple of times.
Don't have the knees for it anymore.