San Bruno Mountain

Spring Summer Fall Winter


View of San Bruno Mountain from within the park (Public Domain)

Description

In the fall many birders spend considerable time and expense in frantic trips to such well-known vagrant traps as Point Reyes. However, with a much smaller investment of time and money, they can spend a rewarding day of vagrant-hunting practically in their own back yard. In fact, this nearby birding spot can be enjoyed any time of the year.

San Bruno Mountain is located at the border of San Mateo and San Francisco counties, but lies entirely in San Mateo County. It extends approximately two thirds of the way across the peninsula in a southeast to northwest direction. The mountain is actually two parallel ridges: a main ridge with a summit of 1314 feet and a lower ridge known as Guadalupe Hills just to the north. At the southeast extent of the mountain the ridge plunges into San Francisco Bay at Sierra Point. To the northwest, the ridge ends in the urban sprawl of Daly City.

The ridges are crossed by innumerable hiking trails and contain many micro-habitats so that an entire book could be devoted to this one mountain. I have selected two walks that offer the best birding with the hope that you will take the time to explore other areas on this fascinating urban mountain.

The Saddle Walk is best if you only have a morning to spend. The saddle area between the ridges was established as a state and county park in 1985. There is a $5 fee. The park has the best birding habitat on the mountain. The area was once a dairy farm and many cypress and eucalyptus were planted as windbreaks. Today these mature trees provide excellent habitat for resident and migrating birds. A bog and nearby intermittent stream and their accompanying willows provides habitat diversity. Unlike other areas on the mountain this walk is level and is ideal for birders of all ages and physical condition.

Leave the parking area (#1) and take the service road north toward the Edward Bacciocco, Jr. Day Camp (#2). During the spring, this road provides great birding. Look in the brambles, cypress and eucalyptus that border this route for nesting Bullock's Oriole, Winter Wren, Purple Finch, Wrentit, Song Sparrow, Pine Siskin, several warbler species, Olive-sided Flycatcher, an amazing number of Allen's Hummingbirds, and other local breeding birds. Spring migrants in this stretch have included Western Tanager, Black-headed Grosbeak, Ash-throated Flycatcher, Varied Thrush, and Warbling Vireo. Even a small flock of Lawrence's Goldfinch, which normally shun the coast for the dryer inland areas, and a high-altitude loving Hammond's Flycatcher have been spotted along the road. In the fall you can expect anything along this road, including some very edible blackberries (a true birding bonus). At the Day Camp turn-around, check the willows and blackberries on both sides of the road. Spring birds here have included Lazuli Bunting, Lark Sparrow, Willow Flycatcher, and ten species of warblers, including a Northern Parula. Occasional flocks of Red Crossbills have been observed in the nearby cypress.

In the fall, this area has produced a White-throated Sparrow, a Yellow-breasted Chat, and a Rose-breasted Grosbeak. If you follow the trail past the turnaround, you enter into a flat grassland and shrub area dominated by gorse. California Quail, California Towhees, White-crowned Sparrows and Song Sparrows nest here. Northern Mockingbirds forage over the grasslands and a Grasshopper Sparrow was seen in the gorse in 1991. In the boggy areas you can hear the Common Yellowthroat defending its territory. In wet years, a small pond has been a nesting site for a pair of Mallards and a winter home for a pair of Wilson's Snipe. Occasionally glance upward and you may be rewarded with a view of one of the many raptors that sail over this area. Northern Harriers, White-tailed Kites, Red-shouldered Hawks, Merlins, Osprey as well as a resident pair of Red-tailed Hawks have frequented the area.

From here backtrack to the parking lot and take the Old Guadalupe Trail (#3). This road splits what is called the Fog Forest, a very damp area that is home to many Winter Wrens. In May and June you are serenaded by the ethereal song of Swainson's Thrush as well as those of many nesting warblers. Look for the nesting Red-tailed Hawks high in the cypresses. A wintering American Redstart was found feeding among the Leather Ferns growing on the cypress trunks here on a Christmas Count. Another American Redstart was discovered further along the trail one spring.

Continue along the trail past the connecting Bog Trail until you reach the stretch of the trail bordered by acacia shrubs. Take some time here, especially in the spring. One late April morning, a single 20 foot acacia shrub produced 7 species of warblers at one time (including a Hermit, Black-throated Gray and Yellow Warblers). In the same area a spring Gray Flycatcher proved to be only the third county record for this bird. It is an excellent habitat for Empidonax flycatchers in general. Search the adjacent eucalyptus grove in the spring for Western Tanager and Ash-throated Flycatcher. Many migrants and resident birds take advantage of the abundant insect life found on the acacia.

Follow the Old Guadalupe Trail through a large grove of eucalyptus (noted for Great Horned Owls and wintering Cedar Waxwings) or backtrack to the Bog Trail (#4). The Bog Trail loops around a small creek with a quarter mile stand of willows. It is a perfect way to end the hike. In the spring, nesting Orange-crowned and Wilson's Warblers abound here, and migrant MacGillivray's Warblers may be seen. Once again, the singing of the Swainson's Thrush fills the air as does the song of the nesting Purple Finch. You can expect to find all the spring and summer resident riparian birds of the Bay Area in these willows with an occasional surprise, like the summer record of the especially rare Hooded Warbler. Since then I cannot walk past these willows in the spring and fall without the great anticipation of finding a particularly intriguing rare species.

As you return to the parking lot in the spring, you should be able to hear singing Common Yellowthroats below you in the bog, and in the fall, Lincoln's Sparrows are found in the baccharis. If you are very lucky, you may spy a secretive Green-tailed Towhee scurrying through the brush. There are two records of this high desert bird on San Bruno Mountain. One of those sightings was made here near the parking area.

Walking the Main Ridge (#5) is truly an exhilarating experience. After you enter the park, turn left, drive under the parkway and continue to a parking area at the summit of the main ridge. From this vantage point the entire San Francisco Bay Area is at your feet and the view is spectacular. From the parking area, take the trail east. This runs along the entire length of the ridge until its end above the community of Brisbane. Birds along this walk are typical of the coastal scrub: Spotted Towhee, Bewick's Wren, California Towhee, Song Sparrow, Western Scrub-Jay, and a plethora of Common Ravens. Resident raptors include Red-tailed Hawk and American Kestrel. In winter Hermit Thrush and Fox Sparrow use the scrub. But during the fall and spring migrations be ready for quite a variety of unusual species. Observations during the spring have produced as many as thirty-three Ospreys, a rare Northern Goshawk, numerous Sharp-shinned and Cooper's Hawks, a Prairie Falcon and even a very unusual adult Bald Eagle. A pair of Northern Harriers have nested on the north slope just below the buildings at the extreme northwest end of the ridge. The fall raptor migration doesn't produce the numbers typical of Hawk Hill in the Marin Headlands, but a morning spent watching raptors from the ridge will provide both the expected migrants and a few surprises, like a Broad-winged Hawk, a dark phase Ferruginous Hawk, Merlin or Golden Eagle, all of which have been observed in previous years. Keep your eyes and ears open for migrating passerine species, especially in the fall. Several species of swifts have been seen and heard, as well as unusual coastal migrants like Evening Grosbeaks and Purple Martins. A migrant White-faced lbis was once seen circling the summit several times before heading south. The easternmost half of the ridge is open grassland habitat with wintering flocks of Horned Larks (otherwise rare in San Mateo County) and Western Meadowlarks with an occasional White-tailed Kite hovering overhead. A particular surprise was a winter record Sage Thrasher observed on the ridge trail above Brisbane. The gullies on the southeast slope have harbored Rock Wren and the canyons sloping to the northeast have had wintering Blue-gray Gnatcatcher. The two prominent canyons just west of Brisbane are Buckeye and Owl Canyons and are noted for a remnant coast live oak woodland, including live oak, California Bay, Holly Cherry, and California Buckeye. Unless you have a high tolerance for Poison Oak and an excellent cardiovascular system these canyons are best explored by approaching cross country from Brisbane rather than dropping down from the ridge trail. The two canyons are not heavily birded, but should be!

At this point, (unless you have left a second car parked along Old Bayshore or you are particularly adventuresome) you must retrace your steps back to the summit parking lot.

A word of caution is necessary for the Ridge Trail. Mornings can be deceptively warm, but a strong and cool afternoon breeze can make the return trip a bit uncomfortable. Take a jacket.

One would be remiss in not mentioning the spectacular wildflower display San Bruno Mountain puts on in the spring. From late February to well into May the mountain is a botanist's delight. Some of the plants are endemic to San Bruno Mountain, and others are rare or endangered everywhere else in the Bay Area. Rare and endangered plants in the park include Coast Rock Cress, Montara Manzanita, Pacifica Manzanita, San Bruno Mountain Manzanita, Franciscan Wallflower, San Francisco Owl's Clover, and San Francisco Campion. The open areas are a riot of color. In addition to the flowers, you may get fleeting glimpses of the Mission Blue and the San Bruno Elfin, two of the four endangered butterflies you might encounter on your walk. Both depend on the endemic flora of San Bruno Mountain for their survival. In the spring, it is wise to bring your camera as well as your binoculars.

Look For These Birds

Mallard, California Quail, Great Blue Heron, Turkey Vulture, Osprey, White-tailed Kite, Red-tailed Hawk, Northern Harrier, Sharp-shinned Hawk, Cooper's Hawk, Red-shouldered Hawk, American Kestrel, Merlin, Peregrine Falcon, Wilson's Snipe, Caspian Tern, Rock Pigeon, Band-tailed Pigeon (uncommon at this location), Mourning Dove, Great Horned Owl, Vaux's Swift (migration), White-throated Swift, Anna's Hummingbird, Allen's Hummingbird, Acorn Woodpecker (accidental at this site), Red-breasted Sapsucker, Downy Woodpecker, Hairy Woodpecker, Northern Flicker, Olive-sided Flycatcher, Western Wood-Pewee (migration), Pacific-slope Flycatcher, Black Phoebe, Say's Phoebe, Ash-throated Flycatcher (migration), Cassin's Vireo (migrant), Hutton's Vireo, Warbling Vireo, Loggerhead Shrike, Tree Swallow, Violet-green Swallow, Northern Rough-winged Swallow, Bank Swallow (rare here), Cliff Swallow, Barn Swallow, Western Scrub-Jay, American Crow, Common Raven, Chestnut-backed Chickadee, Bushtit, Red-breasted Nuthatch, Pygmy Nuthatch, Brown Creeper, Bewick's Wren, Pacific Wren, Golden-crowned Kinglet, Ruby-crowned Kinglet, Blue-gray Gnatcatcher, American Pipit (rare at this location), Swainson's Thrush, Hermit Thrush, American Robin, Varied Thrush, Wrentit, Northern Mockingbird, Cedar Waxwing, European Starling, Orange-crowned Warbler, Nashville Warbler, Yellow Warbler, Yellow-rumped Warbler, Black-throated Gray Warbler, Townsend's Warbler, Hermit Warbler (rare migrant), MacGillivray's Warbler, Common Yellowthroat, Wilson's Warbler, Western Tanager, Spotted Towhee, California Towhee, Savannah Sparrow, Fox Sparrow, Song Sparrow, Lincoln's Sparrow, Grasshopper Sparrow (rare at this location), Golden-crowned Sparrow, White-crowned Sparrow, Dark-eyed Junco, Black-headed Grosbeak, Lazuli Bunting, Western Meadowlark, Red-winged Blackbird, Brewer's Blackbird, Brown-headed Cowbird, Hooded Oriole, Bullock's Oriole, Purple Finch, House Finch, American Goldfinch, Lesser Goldfinch, Pine Siskin, Red Crossbill (irruptive), House Sparrow, Brewer's Sparrow, Rose-breasted Grosbeak, Black Swift

Rarities Seen Here

In this guide, "rarities" are defined as those species given an County Abundance Code of 4, 5, or 6.

Greater White-fronted Goose (fly over), Ring-necked Pheasant (2012), White-faced Ibis (accidental), Bald Eagle, Northern Goshawk, Broad-winged Hawk (fall migration), Swainson's Hawk (migration), Ferruginous Hawk (migration), Golden Eagle, Prairie Falcon (2017), Greater Roadrunner (officially extirpated from county, but last observed here in the 1940s), Burrowing Owl, Common Poorwill, Black Swift (migration), Chimney Swift (2011), Rufous Hummingbird, Calliope Hummingbird, Willow Flycatcher (2013), Hammond's Flycatcher (2011), Dusky Flycatcher, Gray Flycatcher, Western Kingbird, Purple Martin (accidental), Horned Lark, Rock Wren, Mountain Bluebird (accidental), Gray Catbird (2010), Sage Thrasher (accidental), Northern Parula, Chestnut-sided Warbler (2011), American Redstart, Hooded Warbler, Lucy's Warbler (2002), Yellow-breasted Chat, Green-tailed Towhee, Sage Sparrow, Clay-colored Sparrow, Chipping Sparrow (rare migrant at this location), Lark Sparrow, Vesper Sparrow, Sage Sparrow, White-throated Sparrow, Scarlet Tanager, Rose-breasted Grosbeak (2011, 2012), Lawrence's Goldfinch, Evening Grosbeak (2011)

Birding Area Map

Directions

There are two access routes to the park: east and west.

Eastern Access. If you're traveling from the south on Highway 101 take the Brisbane turnoff and travel north on Old Bayshore past Brisbane to Guadalupe Canyon Parkway. Turn left, and travel to the crest where the San Bruno Mountain State and County Park is located. From the north on Highway 101 take the Sierra Point turnoff, and follow Lagoon Rd. to the intersection of Old Bayshore. Turn right at Old Bayshore and proceed north to Guadalupe Canyon Parkway. Turn left, and continue to the park.

Western Access. From the south take I-280 north toward Daly City and take the Mission Street exit. Turn left for one block to San Pedro Road. Turn right on San Pedro Road to Mission Street. After you cross Mission Street San Pedro Road becomes East Market Street. Stay on East Market Street until it becomes Guadalupe Canyon Parkway. Continue east on the Parkway to the crest where the park is located. From the north take I-280 south to John Daly Boulevard. Travel east on John Daly Boulevard to Mission Street. Cross Mission Street where John Daly Boulevard becomes Hillside Boulevard. Stay on Hillside Boulevard until you reach East Market Street. Turn left on East Market Street, which shortly becomes Guadalupe Canyon Parkway. Continue east on the Parkway to the crest where the park is located.

Interactive Map

Red Markers: Parking Area or Trail Head
Hover mouse pointer over marker, or click marker, for identification.

Fees

There is a day-use entrance fee to the park, for $5.00. This is one of the very few state parks that does not accept the Annual Day Use Pass; however, it does accept the County Park membership card.

Hours

The park opens at 8:00 am, and closes a bit before sunset; the confusing particulars of this closing hour can be parsed on the county park website.

Hazards

Plan on being exposed to wind and cold and then take great delight when you aren't. Fall and spring are beautiful, with only occasional fog and usually warm mornings. Winter is relatively mild much like anywhere else in the Bay Area, but it can turn rainy and cold without warning. Summer days can be treacherous. It is often cold and windy with blowing fog even when the rest of the peninsula is in the eighties.

The lower trails have poison oak present, as well as ticks. Rattlesnakes are present; Mountain Lion is not impossible, but neither is it likely.

Facilities

The only facilities on the mountain proper are located in San Bruno State and County Park. Here you will find picnic tables, restrooms and a telephone. Of course, plentiful restaurants and grocery stores are available in both Brisbane and Daly City.

Contact

650-363-4020, or 650-363-4021 (State Park)
(650)992-6770 (County Park)
Street Address: 555 Guadalupe Canyon Parkway, Brisbane 94005

Links

Avian Research Status

San Bruno Mountain County Park is a hotspot in eBird, with data in over 75% of time quadrants. Continue to enter sightings on eBird, especially when dealing with an important ecological site like this one. A subsidiary hotspot, listed as San Bruno Mountain--South Side, has a good selection of data from December through April. When the two hotspots are combined, they yield 105 total species.

San Bruno Mountain is most celebrated in scientific research history for the work done here on butterfly conservation; see links above.

Colma Creek Headwaters Restoration in the park deals with bird habitat; see link above.

As indicated in the description of San Bruno Mountain, this is one of the best county viewing sites for raptor migration in fall. Because San Mateo county lacks a single funnel point for migrating raptors, the numbers and variety of birds to be seen at San Bruno Mountain cannot rival that of Marin County's famed Hawk Hill. But being knowledgeable about the patterns of raptor migration at that northern site can help arm local viewers with a sense of what to expect. The Golden Gate Raptor Observatory maintains excellent records, which can be accessed at their website.

Additional Photos


Birders on trail, June 2007 (Sonny Mencher)


Pacific Wren, June 2007 (Sonny Mencher)


Spotted Towhee, June 2007 (Sonny Mencher)


Be Careful, Poison Oak, June 2007 (Sonny Mencher)


White-tailed Kite, November 2010 (Bruce Grosjean)


Author: John "Mac" McCormick, Uploaded: March 24th, 2009
Last Update: March 11th, 2017, 9:20am. Updated by: light edit by Jennifer Rycenga


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