Endure Sisyphean ascents and descents enroute to one of Los Angeles County's finest waterfalls: Fish Canyon Falls.

One of L.A. County's most attractive waterfalls, Fish Canyon Falls in the San Gabriel Mountains, lies today in a canyon whose mouth has been ripped apart by large-scale quarrying operations. Once beyond the canyon's gaping, barren mouth, however, is a sylvan scene so enchanting it must be seen to be believed.

During the 1980s and most of the '90s, public access to the canyon was made difficult or impossible by operations at the quarry. Access was restored in 1998 when the city of Duarte opened a new trail bypassing the quarry on the canyon's steep west wall. Unfortunately, the devilish climb and descent on this trail -- which must be accomplished twice during the 8.8-mile round trip to and from the falls -- occupies almost three fourths of the time and energy expended on the entire hike. If you go early on a Sunday morning, as I did, you will likely be mercifully free of the quarry noise.

To reach the Fish Canyon trailhead, drive north on the 605 Freeway to its end in Duarte. Head east on Huntington Drive to Encanto Parkway. Turn left and follow Encanto northeast for 1.4 miles. The parking area is just short of the quarry entrance. A helpful brochure with topographic map can be found at an information board a couple of minutes down the trail from the parking lot. Just beyond there, climbing begins in earnest on a primitive, switchbacking trail that at times barely gains purchase on the soft dirt of the 40-degree slopes. Relief from the heart-pounding effort comes at a flat spot on the ridge above (1.3 miles) where you may catch one last panoramic glance behind you of nearly the entire San Gabriel Valley.

Next, the trail sidles up along the quarry fenceline for a while. Then it veers left, following an old firebreak. Next comes a sharp right turn up a ridge. At nearly two miles from the start, you start descending a series of knee-banging switchback segments, nearly as steep as those you climbed, down along an east-facing slope liberally sprinkled with poison oak. At 3.0 miles you reach bottom, and the main trail turns abruptly left (north), following the west wall of Fish Canyon.

Now comes the payoff: the remainder of the trail is delightful with its gentle ascent, superb scenery, and historical reminders. Notice the old cabin foundations, rock and mortar walls, and rusty household equipment. It's hard to believe the narrow canyon once harbored dozens of vacation cabins. Check out the botanical evidence: nonnative ivy, vinca, trees-of-heaven, agaves, and ornamental yuccas. Plenty of native vegetation thrives here, too. Live oaks, bigleaf maples, and bay laurels cling tenaciously to the canyon's precipitous walls.

After 1.1 miles in the canyon itself, the trail crosses over the creek to the east bank. A final 0.3-mile stretch leads to a point offering a fine but not intimately close view of Fish Canyon Falls. The water tumbles nearly 100 feet down a cliff with four separate tiers, slides through riparian vegetation a short way, and makes a final, small leap into a crystalline pool just below the trail.

On the return, you must retrace your steps exactly and refrain from taking a shortcut through the quarry.