My friends had two particular hikes in mind, but we had three days, so we asked the proprietor of the local gear shop for advice - something for three fit hikers, but one that wouldn't tax the poor sea-level gal. One of his suggestions was the Bear Creek trail as far as the Grizzly Mine, 2.4 miles one way, which didn't go above 10,000 feet.
The trail began by crossing the highway over a tunnel before heading up the side of a canyon. The first half or so is cut into a steep slate hillside. While the trail was rocky, it was flat slate that clinks pleasantly underfoot. The walls of the canyon were so severe that there were impressive views even in the trees. Eventually, the trees petered out altogether. The trail was exposed along the right side, although the trail was wide enough to assuage anxiety. (Mind you, I wouldn't want to do it drunk or at night.) We reached the remains of the mine and poked around. The mine shaft was actually visible, although gated and locked.
The trail is named for the creek it runs above, but the key is "above" - we would have had to rappel down several hundred feet to refresh our water bottles. As we hiked, we mused about how hard it would have been to build the trail; turns out the trail was built by miners, in places using dynamite.
The hike was sparser in vegetation than the rest of our hikes, which made it interestingly different. There were a few wildflowers, actually, but it's not a flower hike. Do this one for the spectacular views and the ledge-walking, which looks much more fearsome in photos than it does on the trail.