Really this is an unpaved access road, not a trail – but it’s a great spot to see a wide variety of wildflowers right now. In fact, it is the steep road cut that seems to account for much of the diversity. From the weedy forget-me-nots growing along the seep spring near the beginning of the road, you’ll pass through many different combinations of sun, shade and soil. The level road curves around the canyons and hills of the Marin Municipal Water District, and different flowers appear around every curve. I went out with my parents (happy mother’s day mom!) and we saw jewel flower, Chinese houses, Larkspur, linanthus, woodland star, iris, and many many more. There was a dry, rocky hillside with tall sticky monekyflower bushes laden with blooms, through which a morning glory vine had grown so its large white flowers floated on a sea of orange. In a damp ravine, crimson columbine grew in a garden of other flowers including purple iris and forget-me-nots. When I got home, my plant list had 81 species on it, and 53 of those had been in flower!
This is an easy hike since it’s flat, but you can turn it into a more vigorous outing by connecting up 
with the network of trails that extends down into Deer Park or up onto the rest of the MMWD property – you could go all the way to the top of Mt. Tam if you wanted to!
To get there, head up the Bolinas-Fairfax road as if you were going to Bon Tempe Lake, but at the turnoff to the lake instead park in one of the limited pullouts on the downhill side of the road. Concrete Pipe Trail starts on the other side of the gate.
Flowers Of Marin 