there are quite a few hiking trails that connect into this trail coming up the mountain from your left you will go about 6.5 miles and then a sign post will mark the Rattlesnake down hill section, take this down and it will drop you about .7mi from the toll booth.
Head up Mill Creek Canyon, Trail starts at the elbow on the left of the road, which is about 1.4 miles past the winter gate
http://www.singletracks.com/item.php?c=1&i=8307