Okay, so this trail combination is quite a mixed bag. The beginning is on broad, heavily used trails up to the Danielson's Monument. From there, you pick up the single track Tri-Peaks trail (unmarked) which is hidden behind the burned down ranch house to the left.
This trail is a refreshing change from the area burned out in the May 2013 fire. Lots of shade, through heavy brush and oak groves at lower elevations. It is washed out in places but easily hiked. I would call it moderate difficulty because of the elevation gain and washed out trail. As you ascend, shade becomes more scarce but you remain outside the fire zone. After a couple false summits and beautiful overlooks you arrive at the summit of Boney, where you can scale the boulders and enjoy a 360-degree view of the Conejo Valley, Oxnard Plain, the Santa Monica Mountains and the Pacific.
Most people turn back and return on the same trail. This guide depicts a loop back to the Old Boney Trail, which looked more interesting. WARNING: this trail is traveled lightly, and is not marked. When you cross rock faces, take care to find the real trail down--it is often obscured and there are a lot of false trails to overlooks. This portion of the trail offers some spectacular views BUT is extremely steep in places, with very poor footing in loose stones and soil. I would rate this section DIFFICULT. Very slow going with a very real risk of falling.
Once you rejoin Old Boney Trail the recommended loop turns left to the Fossil Trail with ascends a portion of Sycamore Canyon before rejoining the trail you started out on. Trail guide says this is a ten mile hike. I suspect it's a bit more. We decided to cut out that loop and turned right on Old Boney, hiking straight back towards Danielson's Monument before hiking back where we started. That turned out to be a 9-mile hike, which took over 5-hours with rest breaks.
Like most hikes in this area, starting early is a big plus, as afternoon heat can be taxing.
Enjoy! Be safe!
The Tri peaks part of this is VERY TOUGH steep climbs in Ruts, going down requires hands as it is Steep and in ravines grabbing hold of Branches, roots and rocks. Make sure you have Ap or Maps and GPS as its east to lose trail here.... its hard but WELL worth it. see pics in Danielson Monument trail