No matter what kind of shape you are in, there is a hike at Phoenix Lake for you and your dog. This is also popular place for families and cyclists, but everyone seems to have a smile on.
The main loop around the lake, about three miles in length, is an easy place to start, but there are many other options. If you want to get serious, you can hike all the way to the summit of Mount Tamalpais via Eldridge Grade. Phoenix Lake is one of seven reservoirs operated by the Marin Municipal Water District (MMWD).
Dogs must be leashed and are not allowed to swim or drink from lakes or streams, so be sure to carry plenty of water and come prepared to pick up and pack out any deposits made by your dog.
To reach the trailhead:
From Sir Francis Drake Boulevard at the town of Ross, turn onto Lagunitas Road and follow it to its end at Natalie Coffin Greene Park. Your best shot at nabbing a parking place close to the trailhead is midweek or very early on weekend mornings.