This arching tunnel – 8-feet-tall by 8-feet wide and a straight
1.6 miles long – was dug beginning in 1916, four years after Marin
Municipal, the oldest water district in California, was formed. The
tunnel was completed in 1918.
The tunnel, noted district spokeswoman Libby Pischel, "was
constructed by hand using air drills and horse-drawn and
engine-drawn wagons."
Pine Mountain Tunnel used to carry water from the Lagunitas
Creek area halfway between Alpine Dam and the upper end Kent Lake
to Cascade Canyon, which is just downhill from the Meadow Club on
Bolinas-Fairfax Road.
Today the tunnel is used as a storage tank and can hold nearly
3,000,000 million gallons of water.
[Historical information plagiarized from the Pt. Reyes
Light.]
Aside from the historical interest, this is a pretty, but little
known spot outside of Fairfax. While placing this cache I had
thought of calling it "Wild Iris" because of the incredible wild
irises out here. Unfortunately, 10 months out of the year, no one
would know what the name was about. While beautiful all year round,
spring cachers will be rewarded with an abundance of wildflowers,
and a little known small seasonal waterfall.
This is an easy and pancake flat bike ride on Concrete Pipe fire
road (from the entrance to MMWD on Fairfax-Bolinas road). This can
also be done as a shorter hike from Fairfax-Bolinas road.
The cache itself is about 310 feet beyond the tunnel. Cyclists
will have to walk the last few hundred feet. Cachers will to pass
by a small seasonal creek with nice pools and a small waterfall.
The cache is a short, but easy scramble off a small trail.
There is poison oak in the area. Be sure to check out the
interesting succulents growing on the nearby rock outcropping.
I've listed two waypoints for the easiest access points to find
this cache.
The first one follows a little known hiking trail down to the
cache. In spring time, this has one of the largest collections of
wild irises I've seen, many different colors. Daisy and I passed
hundreds of irises and other wildflowers on the way to place this
cache. The hike is about 1/2 mile from the road.
The second waypoint is the best way to access by bicycle. It is
about a 2 mile +/- pancake flat little used fire road to the cache.
Perfect for novice families and kids. (Concrete pipe fire road is a
great mostly flat easy ride for all cyclists of all abilities, and
it's about 5 miles end to end).
The terrain ratings for this cache are about a 1 by bicycle, and
3 for hiking.
There is also access (on established trails) from Elliot nature
preserve at the bottom of Cascade canyon, but you'll have to do
some map reading, orienteering, and a longer hike.
A link to a handy Marin County Open Space map of the general
area-
http://www.co.marin.ca.us/depts/PK/Main/os/pdf/CascadeCanyonWeb.pdf
Enjoy