Solo hiked on Sep 29 2018.
This is certainly a hard one and NOT recommended for anyone without hiking experience and body strength to hike 20 miles (the map is off by almost 8 miles if you take the full loop). The trail is strait uphill with great view over the ocean and the surrounding mountains.
I did this as a day hike but certainly wouldn’t recommend it. Best would be to camp at one of the campsites (Trail spring camp or the Goad Camp) and hike the day after and make sure to get a chance to see the amazing sky at night.
I camped the night before and after at Limekiln campsite which is a perfect location to start/end this trail. If you take the Limekiln trail from the campsite you can branches off and head to Alvin Trail (it is marked as closed but it was open when I was there) which goes uphill and then merges into the Twin Peak trail.
Left around 7:30 am and took the Twin peak trail and then went to the Cone peak and came down from the Cone peak trail and got back by 6:30 pm. I’m a fast hiker and usually walk faster than an average person, made 4-5 stops to eat and refresh (2 hour combined)so count that in your calculations.
The first half loop to Twin Peak was mostly exposed but the other half was mostly covered. Make sure to take enough water (I took 4.5 Litters which was a bit extra but better to be safe).
The trail is well maintained but some areas were very bushy and tricky to get through, also be careful with poisonous oaks as they are abundant in the area and this trail. The trail from Twin Peak to Cone peak was a bit rocky and I felt lost as it really don’t look much like a trail for 0.1 miles.
I met one person on this hike and had lunch at the Cone Peak and head down at 2:00 pm but he was planning to camp there for the night. Took the Twin Peak trail to go back which turned to be much longer than what I expected.
On my way back looked at Trail Spring camp which seem to be big enough for a group of 6 people but no water although there seemed to be a creek bed which was dry at the time I was there. The Goat camp looked a lot bigger and possibly could fit up to 15 people and had water source nearby.
Beautiful hike but needs experience and love for hiking, highly recommended for 2 days backpacking.