Green Valley to Paso Picacho is a 5.2 mile lightly trafficked loop trail located near Descanso, CA that features a waterfall and is rated as moderate. The trail offers a number of activity options and is accessible from March until October.
Green Valley Falls day use fee is $8.
Nice easy hike.
This trail is beautiful and offers great views of valleys, hills, and the Sweetwater River. The falls themselves are reason enough to visit, but the trail is well worth it. The loop is formed by taking four different trails. I was nervous I was going to get lost but I found a map of it on the San Diego Reader website. You start on the Falls Fire Road. There is a section where you can go down to the falls, but once you do you'll have to come back the way you came. If you do go down to the falls, you might not want to leave :) The Falls Fire road meets with the Sweetwater trail and the California Riding and Hiking Trail. You can go either way. If you go down the Sweetwater trail, you will turn right at the Saddleback trail, right at the California Riding and Hiking Trail, and then meet up at the Falls Fire road. The Sweetwater trail is very narrow and I wouldn't recommend it for mountain biking. When you turn onto the Saddleback trail, you might cross some water. When I was there, someone had made a makeshift bridge out of fallen branches and I managed to stay dry.
UPDATE: Hours after we got home, my husband discovered he'd been bitten by a tick. This trail is overgrown with grasses, so be careful to check for ticks!