East of downtown Los Angeles near Whittier, the 25 mile Skyline Trail travels through three endangered plant communities. Wildflowers are abundant in the winter and spring. This area and 970 acres to the west and south are owned by Rose Hills Foundation and the City of Whittier and a wildlife corridor joint agency of powers are trying to purchase it for a wildlife reserve and corridor. The trail descends into the canyon through an oak woodland and coastal sage scrub mix. The canyon has sycamore trees as well. The trail then climbs up through a toyon/sumac chaparral to the crest of the hill. At this point either return the way you came or continue left along the ridge and then descend the other side to the right into Hacienda Hills Open Space. This leads through some excellent oak woodlands and massive sycamores and there are several options of which way to go. Return the way you came and if you get lost simply head up the hill to the ridge that divided Turnbull Canyon from Hacienda Hills.
To reach the hiking trailhead from Whittier, drive up Turnbull Canyon Road to the intersection with Skyline Drive. Park somewhere along the road and go west down Turnbull Canyon Road toward Whittier until you see a small trail to your right just after the road makes a turn to the right.
Overall, Skyline Trail is the 23rd most popular walking & backpacking of all 88 hiking in California.