The Devil’s Canyon loop allows you to experience the enchanting canyon to be found beyond Red Rock while at the same time escaping the crowds that sometimes end up there. This is possible because the swimmers and sunbathers don’t usually begin to show up until the early afternoon. Starting at 9am (or so) allows you to avoid most people.
Begin the hike by following the gravel road past Red Rock. As you leave the popular swimming hole behind you’ll find yourself walking on what seems like a country road—this one dates back to the days when this area was being developed for its mineral riches—mainly quicksilver. Contorted layers of rock on the north side of the river show the extreme pressures which the shale must have undergone. Underfoot, if you look carefully, you can still find pieces of the red brick quicksilver kilns. Beyond this you’ll find more pools as the road meanders back and forth across the river and through sycamore, cottonwood, and willow groves, meadows, and groves of live oak for several miles to Gibraltar Dam.
When you reach the base of the dam, rather than hiking up the last steep hill to the top of it, head up the road just as if you were returning back to Red Rock on the high road. Fifty yards up the road look for the beginning of the Devil’s Canyon Trail. The canyon is deep and narrow, and for the first half mile has a rugged and wild character to it as it passes through a thick layer of sandstone. Above this the canyon opens, and the trail turns to the right (west) and begins to climb a series of grass slopes as it rises up into the Santa Ynez Fault. Another half mile brings you to the end of Devil’s Canyon and the beginning of Matias Potrero. Continue west of this for 2.5 miles to a trail intersection (marked by a sign). A right turn will drop you down to Paradise Road just a few hundred yards below Live Oak picnic area.
Ray Ford - http://www.sboutdoors.com/devils-canyon.html