Field Trips

CNPS- Yerba Buena Natural History Walks:

Another bountiful bevy of entertaining and informative walks from our visionary leaders in 2020!

All are welcome (some trips you need to register for but most you don't). We're out there...get out there with us!


January 12, SUNDAY, 1-3 pm

San Bruno Mountain Ridge lichens

Leader: Jesse Miller

Lichens are all around us and they have fascinating stories to tell those who listen. Lichens are beautiful, play critical roles in ecosystems, and can act as sensitive environmental indicators because they respond to fine scale ecological conditions. San Bruno Mountain is a particularly interesting destination for lichen explorers; it is an urban conservation success story with significant biodiversity of many taxonomic groups. It has an unusually diverse assortment of lichens, particularly for an urban area, in part because it is high enough above the city that it receives little ambient air pollution, which generally reduces lichen diversity. San Bruno Mountain has particularly high diversity of cyanolichens--lichens with a cyanobacterial partner that are generally especially sensitive to air pollution and play important ecological roles as nitrogen fixers. Participants will learn to identify many common Bay Area lichens to genus, as well as some uncommon cyanolichens such as Lobaria scrobiculata, Sticta spp., Nephroma sp., andCollema sp.  This hike is about 2 miles round-trip (or farther for those who want a longer walk), mostly easy walking on a wide trail and a road with a few steep sections.

Jesse Miller has spent many years working as a botanist and lichenologist across California and the Pacific Northwest. He is currently a lecturer at Stanford, where he teaches ecology. His research interests include studying the effects of global change factors such as altered fire regimes on lichen and plant communities. Jesse loves sharing his passion for the natural world with others and enjoys contributing to Northern California’s growing community of lichen enthusiasts. Website:

Meet at the Summit parking lot, San Bruno Mountain County Park

Entrance fee: $6 to enter park; walk is free, but the instructor will accept donations to support local lichen research. Questions? Email Jesse at


January 18, SATURDAY 10am-1pm

Field Trip - San Bruno Mountain: Saddle and Bog Trails

Leader: Doug Allshouse

This field trip is a first-of-the-year winter staple so let’s start with an easy walk around the saddle and bog with East Bay and San Francisco views. The saddle features grasslands, monocultures of gorse, a eucalyptus forest, the headwaters of Colma Creek, and a rare upland wetland. Several past restoration projects offer vivid examples of success and failure and are worth discussing.  The Saddle Trail is a wide fire road and is rich in plant species and its eastern grasslands share plant species common to the southeast portion of the mountain such as coast iris and purple needlegrass. We should see golden violet and silver lupine, the host plants for the endangered Callippe Silverspot and Mission Blue butterflies. The bog is a rare upland wetland with sedges, rushes, cow parsnip, willows, and creek dogwood.

The Bog Trail may be wet from winter rains so wear appropriate shoes. Bring layers because the Saddle Trail may be windy, but the Bog Trail is generally sheltered. There is a $6 fee (cash or credit/debit card) for park admission payable at the pay station. Meet in the main parking lot which is visible from the kiosk. Heavy rainpostpones to January 25.

For questions, call or text Doug at 415-269-9967 or email

February 1, SATURDAY 10am to 11:30 am

Field Trip - Lobos Creek Valley, Presidio of San Francisco

Leader: Michael Chasse

Lobos Creek Valley has been called "a blazing landmark on the map of Bay Area restoration" (Orion Afield, 2002). The watershed contains some of the best examples of dune and riparian vegetation in San Francisco. Over 20 acres of dune habitat have been restored to support rare plants such as San Francisco lessingia (Lessingia germanorum), dune gilia (Gilia capitata ssp. chamissonis) and San Francisco spineflower (Chorizanthe cuspidata var. cuspidata). Current restoration efforts are focused on the arroyo willow and coast live oak riparian zone along Lobos Creek, a habitat that supports native species such as Pacific wax myrtle (Morella californica), red osier dogwood (Cornus sericea ssp. sericea), lady fern (Athyrium filix-femina), water parsley (Oenanthe sarmentosa), and scouring rush horsetail (Equisetum hyemale ssp. affine). In addition to exploring the restored dunes, this field trip will offer a behind-the-scenes look at recent work in the riparian zone, an area typically closed to the public.

Meet at the Lobos Creek Valley kiosk, located near 1750 Lincoln Blvd in the Presidio of San Francisco. This area is serviced by the Muni 29 bus. There is bike and auto parking in the lot adjacent to 1750 Lincoln Blvd. The hike will involve uneven terrain. Wear comfortable footwear and bring layers. Heavy rain cancels.

Contact Michael at if you have questions.


February 22, 2020, SATURDAY 10 am - 12 noon

Early Spring Walk on Bayview Hill

Leader: Margo Bors

After the winter rains, early spring is a rewarding time to visit Bayview Hill.  The Hill has many early blooming natives including several lomatiums and other members of the carrot or parsnip family.  Johnny Jump-up, in the violet family, host plant of the endangered Callippe Siverspot butterfly, will be in bloom.  We may also see members of the iris, lily and lupine families.  The many California grassland natives in bloom are delightfully visible during this time of year before the grasses become too tall and dense.

The walk up Key Ave. is steep, but we will take our time and enjoy the surroundings.  The upper area is fairly level with fascinating plants, birds and geology, and impressive unobstructed views in every direction. Bring a snack and water and wear layers as temperatures can vary greatly in different areas.  There are no bathroom facilities.

Meeting Place: Key Ave. entrance to Bayview Park, two blocks east of 3rd St.

Transportation: Short walk from MUNI T-Line station at Le Conte & 3rd St.

Contact: Margo Bors, email, phone 415-824-0471


February 29, 2020, SATURDAY, 10:00am – 12:30pm

San Pedro Valley County Park, Hazelnut Trail
Leader: Jake Sigg

The Hazelnut Trail on Montara Mountain offers probably more diversity than any other area around here. A reason for that may be because it contains a rich mix of inland and maritime chaparral in the process of replacing a diverse grassland. In the absence of frequent burning practiced by the indigenous people, woody plants displace the grasses and wildflowers, and you can see that process happening here. We start out from the Visitor’s Center and cross the creek coming down from Brook Falls, cross a thriving riparian woodland, loaded with lush vegetation, then our ascent brings us to a couple of grasslands which will have a few early blooming wildflowers. At this time of year the glory of this trail is the woody plants, and February is the perfect time to visit. Subtlety and restraint—the Japanese term shibui—characterize it. Sage greens, grays, soft browns, blue-greens, copper and an infinity of other hues and textures dominate. Most of the shrubs are still awakening from summer-autumn dormancy. Lichens are a trip and plentiful. Manzanitas and pink currants may be in full bloom. Hazelnuts ditto; pendent male catkins are abundant, and the sharp-eyed may spot red female flowers hiding in the axils of the branchlets—tiny but showy when you focus on them. A favorite—and locally rare—is the chinquapin, a close relative of the chestnut. The underside of its leaves are covered by a rich golden tomentum; in the right light conditions it fills the area with a warm golden glow. This area is remarkably intact in terms of native species. However, building a trail is like opening a wound, where the land is exposed to infection. The only invasive weeds we will see are along this trail. But the trail also allows the wildflowers to persist, so there is much to see continually. This is a single-track trail, so not always possible to keep everyone within earshot. Our policy is “rain or shine, but heavy rain cancels.” If the weather is uncertain on the morning of Feb 29,  call to confirm 415-731-3028.

We will limit the number of people to 15. First come first served; reserve at


March 22, 2020, SUNDAY, 10:00 am - noon

The Natural Wonders of Glen Canyon

Leader: Paul Bouscal

Join us on a spring hike to explore this canyon in the midst of residential neighborhoods. Glen Canyon is one of San Francisco’s significant natural resource areas containing a variety of vegetation including forbs, grasslands, shrubs, willows and other trees. At this time of year we hope to see spring wildflowers in bloom.  The park features rock formations and it is the source of Islais Creek. We will walk and view parts of this 70-acre park to enjoy the flora, fauna and natural history.

Meet at Elk and Chenery Streets. (map) This is approximately a 10 minute walk from the Glen Park BART station. In San Francisco layers of clothing are recommended. Heavy rain cancels.

Contact Paul at, or call 650-438-9109 if you have questions.