Most of the time a hike starts in a valley and leads upwards. This is one is different. You park at the top of Sierra Road and hike downwards. Of course the hard part comes later. I already hike the Boccardo Loop last year. Today, we hiked about 6 miles along the Sierra Vista trail, and the lower and upper Calaveras Fault trails.
(Note: go early, and you will avoid many of the mountain bikers sharing some of the same trails.)