I call it the Sitting Bull short loop because the climb takes you to the rock with the Sitting Bull quote. A beautiful quote I might ad, worth reading. The 15 minutes of steep climbing at the beginning of the hike will make you feel good about having done something for your heart and lungs! The rest of the route is easy walking with just a little bit of downhill. On a clear day, in some places, you will have a 180 degree view of the Bay with the San Francisco skyline in the center.
To get there, drive all the way up Summit Avenue in Mill Valley, and make a sharp left on Fern Canyon Road. When you see the Tamalpa sign on the right, park somewhere near. The hike starts at the sign.
Go up the trail and at the Hoo Koo E Koo intersection, walk straight across the road to go up the rocky path (it's not marked so you have to know it's there). That's the climb! When you reach the Sitting Bull rock, catch your breath, read the plaque, and take in the sight through the trees! Keep going up and shortly thereafter will be another intersection: turn left onto Vic Haun Trail. Follow that path through the woods until you come out and down and see the big tree at the intersection. Make a left toward Hoo Koo E Koo. That road will take you back to where the climb started. There, go right at the sign that points toward Summit Avenue and you will be back at the Tamalpa sign where you started.
Wasn't that great? And you got an hour of exercise! The loop is almost 2 miles and takes about an hour to hike.