Although they slice only about six miles inland from the Pacific shoreline near Point Dume in Malibu, Zuma Canyon and its tributaries harbor some of the deeper gorges of the Santa Monica Mountains. Winter rains turn these summer-dry canyon bottoms into lively little streams. Tucked obscurely into an upper tributary of Zuma called Newton Canyon is a pint-sized but charming waterfall accessible by means of a mere one-half mile of hiking.
To reach the waterfall, begin walking from a large trailhead parking area for the Backbone Trail at mile 9.5 (9.5 miles north of Pacific Coast Highway) on the west side of Kanan-Dume Road. The Backbone Trail, stretching east-west across the length of the Santa Monicas, is nearing completion, with significant work yet to be done west of here. On this segment of the trail you make an easy descent through mature chaparral with an understory of wildflowers and ferns. In just a few minutes you reach the Newton Canyon stream -- which below this point dribbles some 30 feet down a mossy cliff. Off the Backbone Trail to the left you can get a glimpse of this fall from atop some sandstone outcrops, but don't step too close to the edge, where fallen leaves underfoot may precipitate a serious tumble. If you want to reach the base of the fall, it's safer to continue a bit farther west on the Backbone Trail, take one or another trail going left down the slope to the stream below, and then hike a short distance back upstream.
Exploring Newton Canyon's narrow bottom in the downstream direction can be a fun and probably foot-wetting exercise of hopping sandstone boulders and slabs and dodging limbs and branches of oaks, sycamores, and bay laurels. After about 250 yards of such scrambling, you reach the top of another drop-off about 50 feet high, just shy of Newton Canyon's confluence with Zuma Canyon. Stay well away from it. This is the end of the line, so back up and return to the starting point the way you came.