Arrive early, to find parking everything we read before hand stated arrive before 7 am. We arrived around 6:10 am and the parking lot was already full. We found parking down the road. The trail is a bit rocky for the first three or so miles, with some narrow areas. The Icehouse Saddle junction is the first good resting spot with plenty of shade.  There were more hikers than I was expecting. The hike from Icehouse Saddle Junction  was pretty warm with very little shade. There are some switchback before reaching  the Ontario Peak .  We had great views of the Inland Empire. From there we back tracked to the saddle for the Bighorn peak which the trail is not so clearly marked and it is a scramble to the peak.  We climbed over a few logs which are blocking the trail. We just keep climbing up and we reach the peak. There are some good areas to rest just a few feet from the peak with a few trees to give you shade and a break from the sun.