Sierra
Azul Open Space Preserve,
Midpeninsula Regional Open Space District,
Santa Clara County
In brief:
1.4 mile out and back to an overlook with great views of the Sierra Azul, Mount
Umunhum, and the southern Santa Clara valley.
Getting there:
From Interstate 280 in Santa Clara County, exit CA 85 south (exit #12b). Drive
south about 10 miles, then exit Camden Avenue (exit #8). Turn left and drive south
on Camden about 2 miles, then turn right onto Hicks Road. Drive south on Hicks
Road about 6 miles, then turn right at a stop sign onto (unsigned) Mount Umunhum
Road (this is a two-lane road past Guadalupe Reservoir; a small open space parking
lot on the right is visible from Hicks Road). Drive uphill on Mount Umunhum Road
about 2 miles to the roadside pullout on the right side of the road, just before
the gated end of (public access to) Mount Umunhum Road.
Trailhead details:
Parking for 3-4 cars on the side of the road. No drinking water, restrooms, maps,
or designated handicapped parking. There is no direct public transportation to
this trailhead.
Gas, food, and lodging:
Gas, pay phone, and stores back on Camden Avenue. No camping in the preserve.
Rules:
Trails are multi-use. Although dogs are permitted on some trails at this preserve,
they are not allowed on the trails departing from this trailhead. The preserve
is open from dawn to 1/2 hour after dusk.
Distance, category, and difficulty:
This 1.4 mile out and back hike is exceptionally easy, with only about
75 feet in elevation change. Most other hikes at Sierra Azul are long and tough.
The Official Story:
MROSD's Sierra
Azul page
MROSD's field office 650-691-1200
Map Choices:
• Use AAA's San Francisco Bay Region map to get there.
• Map
from MROSD (download the pdf)
• This hike is described and mapped in 60 Hikes within 60 Miles: San Francisco,
1st edition, by Jane Huber (yup, that's me, the creator of this website). Order
this book from Amazon.com. A different Sierra Azul hike is described in the
book's 2nd edition (order
this book from Amazon.com.)
• 
Peninsula Tales
and Trails, by David Weintraub (order
this book from Amazon.com) has an overview of the preserve, descriptions of
hikes, and simple maps.
• South Bay Trails, by Jean Rusmore, Betsy Crowder, and Frances
Spangle (order
this book from Amazon.com) has a simple map and a few suggested hikes.
• The Santa Cruz Mountains Trail Book, by Tom Taber, has a map and
park description (order
this book from Amazon.com).
Bald Mountain Trail
in a nutshell -- a printable, text-only guide to the featured hike.
View
photos of this hike.
Sierra Azul is a 15,000 acre preserve 
unknown
to many bay area outdoor enthusiasts. Although thousands of south bay residents
drive past the preserve daily, and the highest peak, Mount Umunhum strikes a conspicuous
profile, Sierra Azul still receives relatively few visitors. It is a fragmented
preserve, with a fractious surrounding community, and some of the property is
fraught with unsafe conditions. Most of the land now belonging to MROSD was part
of the defunct Almaden Air Force Station, and the summit of 3486 foot Mount Umunhum
remains off limits, closed due to hazardous materials and structures. As of this
date the Air Force has ignored pleas from the community and MROSD to clean up
some old buildings and remove toxic contaminants. A square structure looming above
the summit of Mount Umunhum (some say it looks like a giant sugar cube) makes
the mountain easy to identify from almost anywhere in the south bay, but for many
it's just a daily reminder of the Air Force's desecration of a sacred peak Ohlone
Indians called "resting place of the 
hummingbird."
The heart of the preserve stretches in a continuous swath
from Lexington County Park at Lexington Reservoir east to Almaden Quicksilver
County Park and south almost all the way to the summit of Loma Prieta. Some smaller
parcels, separated from the main area by intervening private property, are isolated
to the west, near Lake Elsman. Private property conflicts developed after the
Air Force abandoned Mount Umunhum in 1980. In 1986 MROSD began purchasing land
at the summit and on both sides of Mount Umunhum Road. Some property owners, with
inholdings deep in the mountain, claimed Mount Umunhum Road as a private drive,
and no trespassing signs sprouted at the junction with Hicks Road. (Conduct a
Google groups search with Umunhum as a keyword to access perhaps apocryphal stories
about unpleasant confrontations between property owners with guns and "trespassers.")
MROSD
is attempting to remedy any and all property conflicts by steadily buying parcels
of land throughout the Sierra Azul, and to date the combined acreage
makes the preserve the 7th largest park/preserve in the bay area. But most of
this preserve is a destination for only the hardiest hikers and cyclists
(or groups with car shuttles), with steep and long fire roads ascending
the mountainous slopes. An expanded trail network is expected in the future, but
currently there are just 6 trails. A trip from a roadside pullout on Hicks
Road to Lexington Reservoir is over 11 miles one way, and the shortest
loop is more than 4 miles, with a 700 foot elevation gain. This moderate loop
could be a good initial hike for Sierra Azul newcomers, but Overgrown Trail,
part of Lexington Reservoir Park, has been closed since 2001; you'll have to settle
for an out-and-back hike on Priest Rock Trail. For sheer ease, no path tops the
out-and-back hike to Bald Mountain. This is a hike that the very old and the very
young should be able to accomplish without batting an eyelash.
It's just 0.7 mile to a viewpoint at the end of Bald Mountain Trail, and from
there you have the entire Santa Clara valley at your feet. Visit in spring
for wildflowers, and in winter for blossoming manzanitas.
Start at the roadside parking area, then cross
Mount Umunhum Road and walk a few feet back downhill to gate SA07. Once you
squeeze between the gate and guardrail, you'll find yourself in a broad flat grassy
area. The hillside drops off to the right, and there are unobstructed views south
to Loma Prieta. Sierra Azul means blue mountain range, a description some find
elusive, but on a January visit the forested mountains were indeed tinged with
an azure hue. Heading east on the wide level multi-use trail you'll pass through
a chaparral community of manzanita, sagebrush, poison oak, chamise, coyote brush,
monkeyflower, yerba santa, toyon, pitcher sage, ceanothus, holly-leaf cherry,
California coffeeberry, and shrubby oaks. 
Only
a few full-size trees stand out along the trail, and you might notice a few blue
elderberry and California bay, as well as a patch of sycamores on the right.
Views southeast are blocked by a hillside, but as Bald Mountain Trail leaves chaparral
for grassland, look left at a saddle for a hint of the panoramic views to come.
The trail climbs easily along the side of a hill, then arches left. A few
shortcut paths streak through the grass on the right. Bald Mountain Trail
sweeps to the right, then circles a belvedere and viewpoint at 0.70 mile. From
this little grassy hill, on a clear day you'll have incredible views, from Mount
Tamalpais in the north, east to Mount Diablo and Mount Hamilton, all the way south
to the mountains of Henry Coe State Park. Just at your feet to the east the rolling
hills of Calero, Almaden
Quicksilver, and Santa Teresa seem positively
puny. Highway 101 is visible slicing through Coyote Valley, where distant headlights
sparkle in thin silver ribbons. This viewpoint is an ideal destination for a picnic
on a warm day, but in chilly weather it can get windy. When I visited on a sunny
January day I watched a northern harrier scouring the hillsides, looking for a
snack. When you're ready, retrace your steps back to the trailhead, savoring
the views of Mount Umunhum.
Total distance: 1.40 miles
Last hiked: Friday, January 11, 2002
Go to Bay Area Hiker Home page
unknown
to many bay area outdoor enthusiasts. Although thousands of south bay residents
drive past the preserve daily, and the highest peak, Mount Umunhum strikes a conspicuous
profile, Sierra Azul still receives relatively few visitors. It is a fragmented
preserve, with a fractious surrounding community, and some of the property is
fraught with unsafe conditions. Most of the land now belonging to MROSD was part
of the defunct Almaden Air Force Station, and the summit of 3486 foot Mount Umunhum
remains off limits, closed due to hazardous materials and structures. As of this
date the Air Force has ignored pleas from the community and MROSD to clean up
some old buildings and remove toxic contaminants. A square structure looming above
the summit of Mount Umunhum (some say it looks like a giant sugar cube) makes
the mountain easy to identify from almost anywhere in the south bay, but for many
it's just a daily reminder of the Air Force's desecration of a sacred peak Ohlone
Indians called "resting place of the 
hummingbird."
MROSD
is attempting to remedy any and all property conflicts by steadily buying parcels
of land throughout the Sierra Azul, and to date the combined acreage
makes the preserve the 7th largest park/preserve in the bay area. But most of
this preserve is a destination for only the hardiest hikers and cyclists
(or groups with car shuttles), with steep and long fire roads ascending
the mountainous slopes. An expanded trail network is expected in the future, but
currently there are just 6 trails. A trip from a roadside pullout on Hicks
Road to Lexington Reservoir is over 11 miles one way, and the shortest
loop is more than 4 miles, with a 700 foot elevation gain. This moderate loop
could be a good initial hike for Sierra Azul newcomers, but Overgrown Trail,
part of Lexington Reservoir Park, has been closed since 2001; you'll have to settle
for an out-and-back hike on Priest Rock Trail. For sheer ease, no path tops the
out-and-back hike to Bald Mountain. This is a hike that the very old and the very
young should be able to accomplish without batting an eyelash.
It's just 0.7 mile to a viewpoint at the end of Bald Mountain Trail, and from
there you have the entire Santa Clara valley at your feet. Visit in spring
for wildflowers, and in winter for blossoming manzanitas. 
Only
a few full-size trees stand out along the trail, and you might notice a few blue
elderberry and California bay, as well as a patch of sycamores on the right.
Views southeast are blocked by a hillside, but as Bald Mountain Trail leaves chaparral
for grassland, look left at a saddle for a hint of the panoramic views to come.
The trail climbs easily along the side of a hill, then arches left. A few
shortcut paths streak through the grass on the right. Bald Mountain Trail
sweeps to the right, then circles a belvedere and viewpoint at 0.70 mile. From
this little grassy hill, on a clear day you'll have incredible views, from Mount
Tamalpais in the north, east to Mount Diablo and Mount Hamilton, all the way south
to the mountains of Henry Coe State Park. Just at your feet to the east the rolling
hills of Calero, Almaden
Quicksilver, and Santa Teresa seem positively
puny. Highway 101 is visible slicing through Coyote Valley, where distant headlights
sparkle in thin silver ribbons. This viewpoint is an ideal destination for a picnic
on a warm day, but in chilly weather it can get windy. When I visited on a sunny
January day I watched a northern harrier scouring the hillsides, looking for a
snack. When you're ready, retrace your steps back to the trailhead, savoring
the views of Mount Umunhum.