From the parking lot, head west up the hill. The trail is well traveled and not hard to follow. There are several variations along the way as many people have cut the switchbacks and just gone for the straightest path possible. All the trails eventually come together about midway and will continue that way until you reach the Big M. At this point you can take the marked trail around to the right and come up behind the M, or Just go straight to the M from the south.
The trail marked is M trail in its entirety, with the feature (The big M) being at the mid-point. Most people just hike the first half to the M and then turn around and go back down. If you follow the rest of the trail it will drop you at the trailhead for Edison trail, which will take you to the upper parking lot. If you have two cars this might be a good option.
Shared By: Mike Levitsky