Great rainy day hike with rewarding waterfall and beautiful vistas from the fire road. Descent can be a bit tricky, especially if you have a baby strapped to your back, like I did, but overall I highly recommend this trail. Also, be careful not to miss the intersection that takes you back to the portal.
This trail is entirely through the trees and shade. The pups and I loved it! I went counter clockwise. The lower part is along a stream and is mostly flat. There is one steep uphill with stairs and switchbacks, 10 minutes or so running. The return is along a mixed use fire road (not a trail). I did miss the first downhill turn off the fire road to the lower part and just took the next one. That downhill trail was loose dirt and a careful walk. The fire road had water and a dish for the pups, which was a nice surprise.
For parking, I didn't follow Piedmont all the way up to the few parking spots and just parked on Magnolia and ran to the trail.
It seems there are several other trails adjoining this that could make for a longer run or hike. I will run this one again.
I walked the 8+ miles on a cloudy and drizzling morning .. but I give 4 stars on account of the likely great views on a clear day.
This is a glass-half-full / glass-half-empty kind of hike: very easy access to nature because Baltimore Canyon is so close to the center of Marin and right at the edge of Larkspur... but also a bit too close to the urban centers in several places. Nevertheless, there is plenty to enjoy along the way, starting with the walk up Baltimore Canyon and then the short climb to Dawn Falls, and beyond and up to Crown Road (Southern Marin Line). That initial section of the trail is probably the most "intimate' (traffic notwithstanding) and beautiful.
Once on Crown road and for a fairly level section, I headed south for 1 mile to the switchback cut-off up to the Blithesdale Ridge Fire road which I followed North, pass the Hoo-Koo-E-Koo Trail and until I reached the cut-off to Indian Fire Road (high point of the hike). The Blithesdale Fire Road rides the very ridge top and is therefore a bit of a roller-coaster; this is however a good section for sweeping views to the NorthWest on a sunny day.
After the cut-off to Indian Fire road, the Blithesdale Ridge Fire Road descends to the intersection of Hoo-Koo-E-Koo and the Corte Madera trail. I took the fairly steep Corte Madera Trail down to the creek bed and the junction with the (Mountain Bikers favorite) Old Railroad Grade fire road. The trail is narrow and not too easy to navigate with a combination of rocky and roots--rich spots.
I continued down on Old Railroad Grade, turning left at the bottom to climb back up to Blithesdale Ridge by the way of the H Line Fire Road to then retrace my step back quickly to Crown Road. I pursued South on Crown Road all the way to the steep and slippery descent towards Baltimore Canyon and Piedmont Road. From Piedmont road, the last stretch of this hike mostly follows the SouthWest bank of Baltimore Canyon to finally close the loop