U.S. DEPARTMENT OF THE INTERIOR

U.S. GEOLOGICAL SURVEY

Index to Detailed Maps of Landslides

in the San Francisco Bay

Region, California

By RICHARD J. PIKE1

Rapid public access to detailed map information on

landslides in the ten-county San Francisco Bay

region is facilitated by a table keyed to

7.5' topographic quadrangles

OPEN-FILE REPORT 97-745 D

1997

This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards

or with the North American Stratigraphic Code. Any use of trade, product, or firm names is for descriptive purposes

only and does not imply endorsement by the U.S. Government.

This database, identified as "Index to Detailed Maps of Landslides in the San Francisco Bay Region, California," has

been approved for release and publication by the Director of the USGS. Although this database has been subjected to

rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further

analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government

may be held liable for any damages resulting from its authorized or unauthorized use.

1

MENLO PARK, CA 94025
2

Index to Detailed Maps of Landslides in the San Francisco

Bay Region, California

by

Richard J. Pike

Abstract: A table keyed to 171 topographic quadrangles on a new 1:275,000-scale

shaded-relief map speeds access to information on landslide locations in the tencounty San Francisco Bay region. Detailed maps showing individual landslides in

nearly any area of interest can be found quickly by knowing only the name of the

appropriate 7.5' quadrangle. The 70-odd technical reports that contain these maps

may be consulted in the U.S. Geological Survey's Menlo Park library collection.

Introduction

The ten counties that comprise the greater San Francisco Bay region1 occupy some

7600 square miles, exclusive of water bodies, much of it in sloping ground. Most of

the land that is not flat terrain is subject to landslides and other types of slope failure

(Nilsen and others, 1979; Wieczorek and others, 1988). Landslides are much more

common features of the Bay Region landscape than is generally realized. Some

75,000 of them—ranging widely in age, size, and type and degree of activity—have

been mapped within just the ten counties. Depending on location, the number of

landslides identified averages about ten per square mile and varies from zero to 40.

It is often necessary to find out whether a landslide exists at a particular Bay Area

locale. Homeowners, landscape architects, real estate developers, city planners,

building officials, emergency-response personnel, civil engineers, utilities workers,

and others all have occasion to know where the landslides are. Because existing old

and ancient landslides may be reactivated by severe winter storms (Nilsen and

others, 1976), timely availability of information on landslide location can reduce

losses of life and property to the region's expanding population (San Francisco Bay

Landslide Mapping Team, 1997).

Access to Information

Current access to detailed data on landslide locations is poor. Although this

information has been generalized for the Bay region, the coarse-scale maps do not

identify individual landslides (Nilsen and others, 1979; Wentworth and others,

1997). Information on individual landslide occurrences is available, but not readily,

and it does not yet exist in a form that can be retrieved quickly. Rather, the data are

1 Sonoma, Napa, Solano, Marin, Contra Costa, San Francisco, San Mateo, Alameda,

Santa Clara, and Santa Cruz
3

scattered among dozens of paper maps included in the often hard-to-find technical

reports by government geologists. The published lists that include these maps and

reports are no longer complete or current (Nilsen and others, 1979; Alger and Brabb,

1985; Taylor and Brabb, 1986), some of the earlier reports are out-of-print, and few

Bay Region libraries have them.

Detailed maps that show the location of individual landslides in the the San

Francisco Bay region can be consulted by the public at the U.S. Geological Survey's

Western Center library in Menlo Park. These "landslide-inventory" maps, all at

scales of l:62,500 scale (one inch = one mile) or better, have been prepared over the

last 35 years by geologists of the Geological Survey, the California Division of Mines

and Geology, and private consulting firms. The USGS Library has on file some 70

different reports that contain these maps. The area covered by each report varies

greatly, from a small irregularly-shaped fraction of one 7.5' USGS quadrangle to

blocks of many quadrangles. Landslides identified in more than half of the Bay

Region's 171 quadrangles (or those parts of them within the ten-county area) are

mapped at the relatively large scale of 1:24,000 (one inch = 3/8 mile).

Although virtually the entire Bay Region is covered by detailed landslide maps2, it

is not easy to find the map for a particular area of interest. First, no single index

map shows the exact areal coverage of all 70-odd landslide-inventory maps, many of

which overlap. (Such a highly complex index map would be difficult to read.)

Moreover, occasional users of the USGS Western Center library (and other libraries)

will find that landslide reports and maps are not grouped together in one place.

Rather, they exist in different series of Federal and State publications, located in

different parts of the library. One must know which document is needed, its library

call number, and then where to look for it. The process can be time-consuming and

frustrating.

This report enables visitors to the USGS Menlo Park library to quickly find the

detailed landslide map they need. Access to the proper documents is achieved

through a table keyed to standard USGS 7.5' quadrangles—a proxy for a true index

map, plus the library location of each document. It is not necessary to consult either

the library's card catalog or its computer terminals.

Finding landslides in your area

The 70-plus geologic reports compiled here contain all the published landslideinventory maps for the San Francisco Bay region that I have been able to verify.

Table 1 specifies which of those reports cover each of the the 171 quadrangles (or

some fraction thereof) on the accompanying index map (Figure 1). Besides

2 Landslides have not yet been mapped in detail in all parts of the following five 7.5'

quadrangles: Valley Ford and Two Rock in northern Marin Co., and Mindego Hill,

Santa Teresa Hills and Mt Madonna in western Santa Clara Co.
4

quadrangle boundaries, this 1:275,000-scale map—modified from a new shadedrelief image (Graham and Pike, 1997)—carries county boundaries and a major-road

network to aid in locating a specific area of interest. The list of landslide reports

appended to Table 1 includes call numbers and shelf locations in USGS's Menlo

Park library. All but a handful of these reports currently are in this library; those few

not shelved at the time of writing will be added as they become available.

A detailed landslide map for all but a few areas within

the ten counties may be found by the following steps:

1. Determine, if not already known, which 7.5' topographic quadrangle(s) cover(s)

the area of interest. Use the index map (Figure 1) or, for greater precision, the

quadrangle maps themselves. (7.5' quadrangles, the Nation's standard reference

maps, show individual streets and roads. All 171 quadrangles for the ten-county

Bay Region are filed alphabetically in the California Center at the USGS Menlo

Park library. Ask a USGS librarian for assistance, if needed.)

2. Go to Table 1 of this report and find the quadrangle name in the alphabetized list

in column 1. Column 3 on the same line has one or more unique ID codes; for

example, "MF344". The ID codes, mostly publication-series numbers, identify the

documents that contain landslide maps for that quadrangle. A bibliography of

these documents, arranged in order of alphabetized ID codes, follows Table 1.

If more two or more ID codes are listed, then more than one map is available for

that quadrangle or parts of it. Be aware that landslide maps differ widely in the

amount of area covered, the shape of that area, and the degree of detail. Check

the document list for the date and scale of the maps indicated. More recent

reports commonly are more complete; most maps will be at 1:24,000 scale (more

detail) or 1:62,500 scale (less detail).

3. The USGS library call number and location of the document are given in boldface

type after each reference in the list. Library locations include stacks (shelves)

numbered from 1 to 35, flat files (map drawers) numbered from 1 to 13, and

unnumbered stacks in the California Center. Identical copies of 14 maps are

shelved in three different locations: stacks 4 and 35 and the California Center.

4. Check the selected report to see that its map covers the area wanted. Small-area

landslide maps commonly include less than 100% of a 7.5' quadrangle or that

part of it lying within the ten-county region. The reduced coverage by local-area

maps is indicated in column 3 of Table 1 by such qualifying terms as "some,"

"minor," or "trace."

Certain large-area maps also include only parts of quadrangles. For example, the

map coded "MF344" has just a small part of the Big Basin quadrangle; the map

coded "CCA75" would be needed to find landslides for most localities in that
5

quadrangle. If one map does not include the area of interest in a quadrangle,

consult other maps indicated by ID codes until the desired coverage is obtained.

Cautions to users — general

This map collection, although an excellent record of the Bay Region landslide

hazard, has limitations. The near-total coverage of the ten-county area does not

mean near-100% identification of the landslides themselves. Most of the maps were

prepared by interpretation of aerial photographs rather than by field study. They are

preliminary or reconnaissance inventories, not exhaustive records of slope failures.

Inclusivity of landslides varies from map to map, depending on date of the

airphotos; publication scale of the map; landslide size, type, age or degree of

degradation; density of tree cover; and each geologist's experience and mapping

philosophy. The maps appended to Table 1 probably underestimate the total

number and extent of Bay Region landslides.

The landslide-inventory maps cited here should be regarded as guides to what

actually may exist on the ground. Indication of a landslide on a map in a particular

locale does not guarantee the presence of an actual landslide. Similarly, the absence

of a landslide on a map does not guarantee that a landslide does not exist on the

ground. The maps indicate what may be expected, but they do not take the place of

an on-site survey or the professional judgment of a licensed engineering geologist

or geotechnical engineer.

Cautions to users — debris flows

Most landslides on the inventory maps described in this report are of the types

collectively referred to as "slides" and "earth flows"—which may move slowly

during, and even weeks to months after, the Northern California rainy season

(Wentworth and others, 1997). The landslide maps referenced here include

comparatively few of the type of slope failure known as a "debris flow." Commonly

called "mudslides", debris flows are small, shallow mixtures of water and soil that

mobilize suddenly during locally heavy rains, quickly sweeping down steep gullies

and leaving thin deposits of material that do not markedly distort the ground

surface. Over time, debris flows may reoccur in the same location.

Debris flows are common in the Bay Area (Wieczorek and others, 1988), but they are

identified on only some of the landslide-inventory maps listed here—the more

recent 1:24,000-scale open-file reports by the California Department of Mines and

Geology. Few debris flows are shown on maps prepared before the Region's most

recent severe winter (1982) because their recognition features are quickly obscured by

vegetation. For example, locations of 18,000 debris flows generated by the January

1982 rains were mapped, but from airphotos taken immediately after the storm

(Wieczorek and others, 1988).
6

Thus, it is not possible to compile a historic inventory of debris flows comparable to

that of slides and earth flows. However, the debris-flow hazard to a particular area

may be evaluated indirectly by other means (Campbell and others, 1994; Mark and

Ellen, 1995; Ellen and others, 1997). Actual reduction of the risk resulting from this

hazard may require real-time analysis and warning (Wilson, 1997; Wilson and

Jayko, 1997).

The Digital Database

No paper maps accompany this document or the other five reports in the San

Francisco Bay Region Landslide Folio. Rather, the Folio is released as a digital

database that can be obtained by either (1) connecting with a USGS Web page, (2)

through anonymous ftp (file transfer protocol) over the Internet, or (3) sending a

request, accompanied by a blank magnetic tape, to USGS. Available in two data

formats (ARC/INFO Export-compatible or PostScript), the map files described here

can be plotted on the user's equipment or that of a commercial vendor.

The digital compilation was performed in ARC/INFO, a commercial Geographic

Information System (Environmental Research Institute [ESRI], Redlands,

California). The database for the Landslide Index comprises a quadrangle-index map

consisting of an ARC/INFO coverage for the ten-county region, a PostScript mapimage file for the region, a PostScript version of this pamphlet, and a text-only

version of the pamphlet. See San Francisco Bay Landslide Mapping Team (1997) for

information about filenames and how to obtain the data and plotfiles.

The data files are as follows:

sfbr-qi.e00 -ARC/INFO Export file of quadrangle index map

sfbr-qi.ps -PostScript map-image plotfile of the index map

sfbr-qi-dbsesc.ps -PostScript version of this pamphlet

sfbr-qi.dbdesc.txt -ASCII text version of this pamphlet

The map database itself is rather simple, consisting of unattributed arcs (quadrangle

grid lines) and polygons with associated quadrangle names; these are stored in

Universal Transverse Mercator (UTM) projection (Table 1). Digital tics, which

define a 7.5-minute grid of latitude and longitude, correspond to corners of 7.5'

quadrangles that fall within the map area.

Table 1 - Map Projection

PROJECTION UTM

UNITS meters

ZONE 10

DATUM NAD27

PARAMETERS none
7

Content of the map database is described in terms of the arcs, polygons, and

annotations comprising the map. Descriptions of the database fields use the terms

explained in Table 2.

Table 2 - Field Definition Terms

ITEM NAME name of the database field (item)

WIDTH maximum number of digits or characters stored

OUTPUT output width

TYPE B-binary integer, F-binary floating-point number,

I-ASCII integer, C-ASCII character string

N.DEC number of decimal places maintained for floatingpoint numbers

Arcs (lines) are recorded as strings of vectors and are described in the arc attribute

table (AAT: Table 3). They define edges of the 7.5' quadrangles. The name of the

table is SFBR-QI.AAT.

Table 3 - Content of the Arc Attribute Tables

ITEM NAME WIDTH OUTPUT TYPE N.DEC.

FNODE# 4 5 B - - starting node of

arc (from node)

TNODE# 4 5 B - - ending node of

arc (to node)

LPOLY# 4 5 B - - polygon to the

left of the arc

RPOLY# 4 5 B - - polygon to the

right of the arc

LENGTH 4 12 F 3 length of arc

in meters

SFBR-QI# 4 5 B - - unique internal

control number

SFBR-QI-ID 4 5 B - - unique identification number
8

Polygons (areas) are described in the polygon attribute table (PAT: Table 4). They

define the areas of the 7.5' quadrangles. The name of the table is SFBR-QI.PAT.

Table 4 - Content of the Polygon Attribute Tables

ITEM NAME WIDTH OUTPUT TYPE N.DEC.

AREA 4 12 F 3 area of polygon

in square meters

PERIMETER 4 12 F 3 length of perimeter in meters

SFBR-QI# 4 5 B - - unique internal

control number

SFBR-QI-ID 4 5 B - - unique identification number

NAME 35 35 C - - unit label

The index-map database also contains annotation. The quadrangle names have

been placed to appear diagonally within each quadrangle polygon.

Acknowledgments:

Earl Brabb and Melanie Moreno contributed to this report. Scott Graham, Carl

Wentworth and Gregg Beukelman created the index map.
9

References

Alger, C.S., and Brabb, E.E., 1985, Bibliography of United States landslide maps and reports: U. S.

Geol. Survey Open-file Report 85-585, 119 p.

Campbell, R.H., Bernknopf, R.L., and Soller, D.R., 1994, Mapping time-dependent changes in soil slipdebris flow probability: U.S. Geol. Survey Open-file Report 94-699, 66 p., map scales 1:24,000

and 1:40,000.

Ellen, S.D., Mark, R.K., Wieczorek, G.F., Wentworth, C.M., Ramsey, D.W., and May, T.E., 1997, Map

Showing Principal debris-flow source areas in the San Francisco Bay Region, California: U.S.

Geological Survey, Open-file Report 97-745 E, map scales 1:275,000 and 1:125,000.

Graham, S.E., and Pike, R.J., 1997, Shaded-relief map of the San Francisco Bay Region, California:

U.S. Geological Survey, Open-file Report 97-745 B, map scales 1:275,000 and 1:125,000.

Mark, R.K., and Ellen, S.D., 1995, Statistical and simulation models for mapping debris-flow hazard,

in Carrara, Alberto, and Guzzetti, Fausto, eds., Geographical Information Systems in Assessing

Natural Hazards: Amsterdam, Kluwer, p. 93-106 and 345.

Nilsen, T.N., Taylor, F.A., and Dean, R.M., 1976, Natural conditions that control landsliding in the San

Francisco Bay Region—an analysis based on data from the 1968-69 and 1972-73 rainy seasons:

U.S. Geol. Survey Bulletin 1424, 35 p., map scale 1:250,000.

Nilsen, T.N., Wright, R.H., Vlasic, T.C., and Spangle, W.E., 1979, Relative slope stability and landuse planning in the San Francisco Bay Region, California: U.S. Geol. Survey Prof. Paper 944, 96

p., map scale 1:125,000.

San Francisco Bay Landslide Mapping Team, 1997, Introduction to the San Francisco Bay Region,

California, Landslide Folio: U.S. Geological Survey Open-file Report 97-745 A.

Taylor, Fred, and Brabb, E.E., 1986, Map showing the status of landslide inventory and susceptibility

mapping in California: U.S. Geol. Survey Open-file Report 86-100, 40 p., map scale 1:1,000,000.

Wentworth, C.M., Graham, S.E., Pike, R.J., Beukelman, G.S., Ramsey, D.W., and Barron, A.D., 1997,

Summary distribution of slides and earth flows in the San Francisco Bay Region, California:

U.S. Geological Survey, Open-file Report 97-745 C, map scales 1:275,000 and 1:125,000.

Wieczorek, G.F., Harp, E.L., Mark, R.K., and Bhattacharyya, A.K., 1988, Debris flows and other

landslides in San Mateo, Santa Cruz, Contra Costa, Alameda, Napa, Solano, Sonoma, Lake,

and Yolo counties, and factors influencing debris-flow distribution, in Ellen, S.D., and

Wieczorek, G.F., eds., Landslides, Floods and Marine Effects of the Storm of January 3-5, 1982,

in the San Francisco Bay Region, Califrnia: U.S. Geol. Survey Prof. Paper 1434, p. 133-162.

Wilson, R.C., 1997a, Operation of a landslide warning system during the California storm sequence of

January and February 1993, in Larson, R.A., and Simpson, J.E., eds., Storm-induced Geologic

Hazards: Case Histories from the 1992-1993 Winter in Southern California and Arizona:

Boulder, Colorado, Geol. Soc. America Reviews in Engineering Geology, v. XI, p. 61-70.

Wilson, R.C., and Jayko, A.S., 1997, Map of rainfall thresholds for debris flows in the San Francisco

Bay Region, California: U.S. Geological Survey, Open-file Report 97-745 F.
1 0

Table 1

Detailed landslide-inventory maps of the San Francisco Bay region,

by 7.5' topographic quadrangle and county

 Name

 of 7.5' County Landslide Map ID**

Quadrangle

Aetna Springs Napa OF76-074

Allendale Solano MF719, some OFR89-17

Altamont Alameda MF321, OF75-277, OFR91-02

Annapolis Sonoma SR120, minor PR16

Ano Nuevo Santa Cruz CCA75, OFR91-05, OFR84-06, trace MF344

Antioch North Solano/Contra Costa MF322, OF75-277

Antioch South Contra Costa MF310, OF75-277

Arched Rock Sonoma PR16, SR120

Asti Sonoma MF594, SR120, trace OF74-238, SR122, & SR142

Benicia Solano/Contra Costa MF595, OF75-277, much OFR86-17, minor OFR95-12

Bethany Contra Costa/Alameda obsolete map name (see Clifton Court Forebay)

Big Basin Santa Cruz/San Mateo most CCA75, minor MF344, OFR91-05, some OFR84-06

Big Foot Mtn Sonoma MF594, SR120

Birds Landing Solano MF322

Bodega Head Sonoma/Marin PR20, SR120, trace OFR72-22

Bolinas Marin OF75-281, some OFR77-15

Bouldin Island Contra Costa MF322, OF75-277

Brentwood Contra Costa MF338, OF75-277

Briones Valley Contra Costa MF493, OF75-277, some OFR95-12

Brooks Napa MF719

Byron Hot Springs Contra Costa/Alameda MF338, OF75-277, OFR92-05

Calaveras Reservoir Santa Clara/Alameda MF339, OF75-277, much CCA74, some MF361

Calistoga Napa/Sonoma OF76-074, SR120

Camp Meeker Sonoma SR120, much OFR81-12

Capell Valley Napa OF76-074, MF719

Castle Rock Ridge Santa Cruz/Santa Clara most CCA75, some OFR72-21, OFR91-05, trace MF643

Cazadero Sonoma OF76-074, SR120

Cedar Mtn Alameda MF321, OF75-277

Chiles Valley Napa OF76-074

Chittenden Santa Clara OFR91-05, some OFR80-11 & OFR94-02, trace PR18, & CCA75

Clayton Contra Costa MF310, OF75-277

Clifton Court Forebay Contra Costa/Alameda MF338, OF75-277

Cloverdale Sonoma MF594, SR120

Cordelia Solano/Napa MF595, OFR88-22

Cotati Sonoma OF76-074, SR120, some OFR72-25, trace OFR86-05

Courtland Solano MF719

Crevison Peak Santa Clara MF416, OF75-277

Cupertino Santa Clara some MF643 & PR17, minor OFR72-21 & CCA74, trace OFR91-05

& CCA75

Cuttings Wharf Napa/C. Costa/Sonoma MF595, minor OFR88-22

Davenport Santa Cruz CCA75, OFR91-05, minor OFR84-06

Davis Solano MF719

Denverton Solano MF322

Detert Reservoir Napa OF76-074

Diablo Contra Costa/Alameda MF310, OF75-277, much OFR86-07, much OFR95-15

Dixon Solano MF719

Double Point Marin OF75-281

Dozier Solano MF719

Drakes Bay Marin OF75-281, trace OFR77-15
1 1

 Quadrangle County Landslide Map ID

Dublin Alameda/Contra Costa MF519, OF75-277, much OFR91-02 & OFR95-14, minor OFR86-

07

Duncan Mills Sonoma SR120, some PR20, minor PR16

Elmira Solano MF719, much OFR89-17

Eylar Mtn Santa Clara/Alameda MF339, OF75-277

Fairfield North Solano/Napa OF76-074, MF719, OFR87-09, OFR89-17

Fairfield South Solano MF595, trace OFR88-22

Felton Santa Cruz CCA75, OFR91-05

Fort Ross Sonoma OF76-074, SR120, minor PR16

Franklin Point San Mateo/Santa Cruz much MF344, CCA75, & OFR84-06

Geyserville Sonoma OF85-711, SR120

Gilroy Hot Springs Santa Clara MF416, OF75-277, minor OFR78-11

Gilroy Santa Clara some MF416 & OF75-277, minor PR18, OFR78-11, & OFR78-12

Glen Ellen Sonoma OF76-074, SR120, some OFR72-25

Gualala Sonoma PR16, SR120

Gude Mountain Sonoma SR120

Guerneville Sonoma OF85-711, SR120

Guinda Napa MF677

Half Moon Bay San Mateo MF344

Hayward Alameda MF519, OF75-277, OFR95-14

Healdsburg Sonoma OF85-711, SR120

Honker Bay Contra Costa/Solano MF322, OF75-277

Hunters Point San Mateo/S.F. MF344, OF65-18, MF311, and OF500

Inverness Marin OF75-281, minor OFR77-15, trace OFR84-22

Isabel Valley Santa Clara MF339, OF75-277

Isleton Solano MF322

Jericho Valley Napa MF677

Jersey Island Contra Costa/Solano MF322, OF75-277

Jimtown Sonoma OF85-711, SR120, minor OF74-238, SR122, & SR142

Kenwood Sonoma/Napa OF76-074, SR120

Knoxville Napa MF677

La Costa Valley Alameda MF519, OF75-277, OFR9x-xx

La Honda San Mateo MF344, minor MF1422

Lake Berryessa Napa MF719

Las Trampas Ridge Contra Costa/Alameda MF493, OF75-277, OFR95-15

Laurel Santa Cruz CCA75, OF89-676, OFR91-05, minor OFR90-06, trace CCA74

Liberty Island Solano MF719

Lick Observatory Santa Clara MF339, OF75-277, much CCA74

Livermore Alameda MF519, OF75-277, OFR91-02

Loma Prieta Santa Cruz/Santa Clara CCA75, OF88-752, OFR91-05, trace CCA74 & OFR72-21

Lone Tree Creek Alameda MF321, OF75-277

Los Gatos Santa Clara/Santa Cruz OF91-593 & OFR91-05, much OFR72-21, some CCA74 & CCA75,

trace MF643 & OFR90-6

Mare Island Contra Costa/Solano MF595, OF75-277, trace PR19

Mariposa Peak Santa Clara MF416, OF75-277

Mark West Springs Sonoma/Napa OF76-074, SR120, much OFR77-13, minor OFR72-25

McGuire Ridge Sonoma SR120, minor PR16

Mendenhall Springs Alameda MF321, OF75-277

Merritt Solano MF719

Midway Alameda MF321, OF75-277

Milpitas Santa Clara/Alameda MF339, OF75-277, much CCA74

Mindego Hill* S.Mateo/S.Clara/S.Cruz MF344, OFR91-05, minor PR17 & CCA75, trace PV

Mississippi Creek Santa Clara MF416, OF75-277, some CDPR

Montara Mtn San Mateo MF344

Monticello Dam Solano/Napa MF719

Morgan Hill Santa Clara most MF416, OF75-277 & CCA74, minor PR18, trace OFR78-12

Moss Landing Santa Cruz CCA75, OFR91-05

Mount St Helena Sonoma/Napa OF76-074, SR120, some CCA76

Mountain View Santa Clara/Alameda minor CCA74 & PR17, trace MF344

Mt Boardman Santa Clara/Alameda MF339, OF75-277
1 2

 Quadrangle County Landslide Map ID

Mt Day Santa Clara/Alameda MF339, OF75-277, trace CCA74

Mt George Napa/Solano OF76-074, MF719

Mt Madonna* Santa Clara/Santa Cruz some PR18, minor CCA75 & MF416

Mt Sizer Santa Clara MF416, OF75-277, some OFR78-12 & CDPR, minor CCA74

Mt Stakes Santa Clara MF339, OF75-277

Mt Vaca Solano OF76-074, MF719, much OFR89-17

Mustang Peak Santa Clara MF416, OF75-277

Napa Napa OF76-074, OFR95-16

Newark Alameda MF519, OF75-277, OFR9x-xx

Niles Alameda MF519, OF75-277, OFR9x-xx

Novato Marin OF75-281, much PR21, some OFR72-22, minor OFR76-02, trace

OFR84-22

Oakland East Alameda/Contra Costa MF493, OF75-277

Oakland West Alameda MF493, OF75-277

Pacheco Pass Santa Clara MF416, OF75-277

Pacheco Peak Santa Clara MF416, OF75-277

Palo Alto San Mateo/Santa Clara MF344, minor W & PV, trace PR17

Petaluma Marin/Sonoma OF75-281, much OFR86-05, trace PR21

Petaluma Point Marin MF595, OFR76-02, PR21

Petaluma River Sonoma/Marin OF75-281, some PR21, minor OFR86-05

Pigeon Point San Mateo MF344

Plantation Sonoma PR16, SR120

Point Bonita Marin most MF574, some OFR72-22, much OFR76-02, some OFR84-

22, trace PP782

Point Reyes NE Marin/Sonoma most OF75-281, much MF1406& PP1434, trace OFR77-15

Port Chicago Contra Costa/Solano obsolete map name (see Vine Hill)

Redwood Point San Mateo/Alameda MF344, minor MF519 & OF75-277

Richmond Contra Costa/Alameda MF493, OF75-277, much PR19

Rio Vista Solano MF322

Rutherford Napa/Sonoma OF76-074, SR120

San Felipe Santa Clara MF416, OF75-277, some OFR78-11

San Francisco North S.F./Marin most PP782 & I-272, minor MF574, minor OFR84-22

San Francisco South S.F./San Mateo most MF344, some OF65-18, MF311, & OF500

San Geronimo Marin OF75-281, minor OFR76-02, trace PR21

San Gregorio San Mateo MF344

San Jose East Santa Clara MF339, OF75-277, CCA74

San Jose West Santa Clara MF339, much CCA74

San Leandro Alameda MF519, OF75-277

San Mateo San Mateo MF344

San Quentin Marin/Contra Costa OF75-281, MF-493, OF75-277, OFR76-02, OFR84-22, PR19

(some of each)

San Rafael Marin OF75-281, much OFR76-02, much OFR84-22

Santa Cruz Santa Cruz CCA75, OFR91-05

Santa Rosa Sonoma OF76-074, SR120

Santa Teresa Hills* Santa Clara CCA74, trace MF416, OF75-277 & OFR72-21

Saxon Solano MF719

Sears Point Sonoma MF595

Sebastopol Sonoma SR120

Skaggs Springs Sonoma obsolete map name (see Warm Springs Dam)

Sonoma Sonoma/Napa OF76-074, SR120

Soquel Santa Cruz CCA75, OFR91-05

St Helena Napa OF76-074

Stewarts Point Sonoma SR120, some PR16

Tassajara Contra Costa/Alameda MF310, OF75-277, OFR92-05

The Geysers Sonoma MF594, SR120, OF74-238, SR122, SR142

Three Sisters Santa Clara MF416, OF75-277

Tomales Marin most OF75-281, much MF1406 & PP1434

Tombs Creek Sonoma OF76-074, SR120

Two Rock* Sonoma/Marin most SR120

Valley Ford* Marin/Sonoma some SR120, minor OFR81-12, minor OFR72-22
1 3

 Quadrangle County Landslide Map ID

Vine Hill Contra Costa/Solano MF595, OF75-277, minor OFR86-17, trace OFR95-12

Walnut Creek Contra Costa MF493, OF75-277, most OFR95-12

Walter Springs Napa OF76-074

Warm Springs Dam Sonoma OF76-074, SR120

Watsonville East Santa Cruz/Santa Clara CCA75, OFR91-05

Watsonville West Santa Cruz CCA75, OFR91-05

Whispering Pines Sonoma OF74-238, SR122, SR142, SR120

Winters Solano MF719

Woodside San Mateo MF344, minor W

Woodward Island Contra Costa MF338, OF75-277

Yountville Napa OF76-074

 * detailed landslide maps are not available for entire quadrangle

** types of reports represented by ID codes:

U.S. Geological Survey (USGS) series

 I = Miscellaneous Investigation Map

 MF = Miscellaneous Field Study

 OF = Open-file Report

 PP = Professional Paper

California Division of Mines & Geology (CDMG) series

OFR = Open-file Report

 PR = Preliminary Report

 SR = Special Report

Other sources

 CCA = Cooper-Clark Associates contract report

CDPR = CA Dept. of Parks & Recreation report

 W = geologic map of the Town of Woodside

 PV = geologic map of the Town of Portola Valley

Documents containing detailed landslide-inventory maps

for the ten-county San Francisco Bay Region,

keyed to Table 1 ID codes in alphabetical order

CCA74 — Cooper-Clark and Associates, 1974, Landslides and landslide susceptibility, in Technical

Report, Geotechnical Investigation, City of San Jose's Sphere of Influence for the City of San

Jose: San Jose, CA, Department of Public Works, p. 17-35 and plates 1-A and 1-B

(landslides), map scale 1:48,000. *203.3(276) Sa522tr [locked stack;

ask librarian]

CCA75 — Cooper-Clark and Associates, 1975, Preliminary map of landslide deposits in Santa Cruz

County, in Seismic Safety Element of the County General Plan: Santa Cruz County, CA,

Planning Department, 1 sheet, map scale 1:62,500. *203.3(276) Sa59s

[locked stack; ask librarian]
1 4

CCA76 — Dwyer, M.J., and Noguchi, Naohiko, 1976, Regional Landslide Map, Geysers-Cow Mountain

Study Area, Mendocino, Lake and Sonoma Counties, California: Cooper-Clark and

Associates, U.S. Bureau of Land Management Contract No. YA-512-LT6-83, Ukiah District

Office, CA, 8 sheets, map scale 1:12,000. recently to library; no number yet

CDPR — Willard, Syd, 1984, Landslide Inventory of the Henry Coe Park: Calif. Dept. Parks and

Recreation, Sacramento, CA, map scale 1:24,000. not yet in library

I-272 — Schlocker, Julius, Bonilla, M.G., and Radbruch, D.H., 1958, Geology of the San Francisco North

quadrangle, California: U.S. Geol. Survey Misc. Geol. Inves. Map I-272, scale 1:24,000.

M(200) vI no.272 stack 35

MF310 — Nilsen, T.H., 1971, Preliminary photointerpretation map of landslide and other surficial deposits

of the Mount Diablo area, Contra Costa and Alameda Counties, California: U.S. Geol. Survey

Misc. Field Studies map MF-310, scale 1:62,500 [BDC 31]. M(200) vMF no.310

stack 35; and (200) Un3sfbd no.31 stack 4 and CA Center

MF311 — Bonilla, M.G., 1971, Preliminary geologic map of the San Francisco South quadrangle and part

of the Hunters Point quadrangle, California: U.S. Geol. Survey Misc. Field Studies map MF311, scale 1:24,000 [BDC 29]. M(200) vMF no.311 stack 35; (200)

Un3sfbd no.29 stack 4 and CA Center

MF321 — Nilsen, T.H., 1972a, Preliminary photointerpretation map of landslide and other surficial

deposits of the Altamont and Carbona 15-minute quadrangles, Alameda County, California:

U.S. Geol. Survey Misc. Field Studies map MF-321, scale 1:62,500 [BDC 34].

M(200) vUn3mf no.321 stack 35; (200) Un3sfbd no.34 stack

4 and CA Center

MF322 — Sim, J.D., and Nilsen, T.H., 1972, Preliminary photointerpretation map of landslide and other

surficial deposits of parts of the Pittsburg and Rio Vista 15-minute quadrangles, Contra Costa

and Solano Counties, California: U.S. Geol. Survey Misc. Field Studies map MF-322, scale

1:62,500 [BDC 35]. M(200) vMF no.322 stack 35; (200)

Un3sfbd no.35 stack 4 and CA Center

MF338 — Nilsen, T.H., 1972b, Preliminary photointerpretation map of landslide and other surficial

deposits of the Byron area, Contra Costa and Alameda Counties, California: U.S. Geol. Survey

Misc. Field Studies map MF-338, scale 1:62,500 [BDC 38]. M(200) vMF no.338

stack 35; (200) Un3sfbd no.38 stack 4 and CA Center

MF339 — Nilsen, T.H., 1972c, Preliminary photointerpretation map of landslide and other surficial

deposits of the Mount Hamilton quadrangle and parts of the Mount Boardman and San Jose

quadrangles, Alameda and Santa Clara Counties, California: U.S. Geol. Survey Misc. Field

Studies map MF-339, scale 1:62,500 [BDC 40]. M(200) vMF no.339 stack

3 5 ; (200) Un3sfbd no.40 stack 4 and CA Center

MF344 — Brabb, E.E., and Pampeyan, E.H., 1972, Preliminary map of landslide deposits in San Mateo

County, California: U.S. Geol. Survey Misc. Field Studies map MF-344, scale 1:62,500 [BDC

42]. M(200) vMF no.344 stack 35; (200) Un3sfbd no.42

stack 4 and CA Center

MF361 — Nilsen, T.H., and Brabb, E.E., 1972, Preliminary photointerpretation and damage maps of

landslide and other surficial deposits in northeastern San Jose, Santa Clara County, California:

U.S. Geol. Survey Misc. Field Studies map MF-361, scale 1:24,000 [BDC 45].

M(200) vMF no.361 stack 35; (200) Un3sfbd no.45 stack

4 and CA Center
1 5

MF416 — Nilsen, T.H., 1972d, Preliminary photointerpretation map of landslide and other surficial

deposits of the Los Gatos, Morgan Hill, Gilroy, Gilroy Hot Springs, Pacheco Pass, Quien Sabe,

and Hollister 15-minute quadrangles, Santa Clara County, California: U.S. Geol. Survey Misc.

Field Studies map MF-416, scale 1:62,500 [BDC 46]. M(200) vMF no.416

stack 35; (200) Un3sfbd no.46 stack 4 and CA Center

MF493 — Nilsen, T.H., 1973a, Preliminary photointerpretation map of landslide and other surficial

deposits of the Concord 15-minute quadrangle and the Oakland West, Richmond, and part of

the San Quentin 7.5-minute quadrangles, Contra Costa and Alameda Counties, California:

U.S. Geol. Survey Misc. Field Studies map MF-493, scale 1:62,500 [BDC 57].

M(200) vMF no.493 stack 35; (200) Un3sfbd no.57 stack

4 and CA Center

MF519 — Nilsen, T.H., 1973b, Preliminary photointerpretation map of landslide and other surficial

deposits of the Livermore and parts of the Hayward 15-minute quadrangles, Alameda and

Contra Costa Counties, California: U.S. Geol. Survey Misc. Field Studies map MF-519, scale

1:62,500 [BDC 59]. M(200)4 vUn3mf no.519 stack 35;

(200) Un3sfbd no.59 stack 4 and CA Center

MF574 — Blake, M.C., Bartow, J.A., Frizzell, V.A. Jr., Schlocker, J., Sorg, D., Wentworth, C.M., and

Wright, R.H., 1974, Preliminary geologic map of Marin and San Francisco Counties and parts

of Alameda, Contra Costa, and Sonoma Counties, California: U.S. Geol. Survey Misc. Field

Studies map MF-574, scale 1:62,500 [BDC 64]. M(200) vMF no.574 stack

3 5 ; (200) Un3sfbd no.64 stack 4 and CA Center

MF594 — Frizzell, V.A., Jr., 1974, Reconnaissance photointerpretation map of landslides in parts of the

Hopland, Kelseyville, and Lower Lake 15-minute quadrangles, Sonoma County, California:

U.S. Geol. Survey Misc. Field Studies map MF-594, scale 1:62,500 [BDC 66].

M(200)4 vUn3mf no.594 stack 35; (200) Un3sfbd no.66 stack

4 and CA Center

MF595 — Frizzell, V.A., Jr., Sims, J.D., Nilsen, T.H., and Bartow, J.A., 1974, Preliminary

photointerpretation map of landslide and other surficial deposits of the Mare Island and

Carquinez Strait 15-minute quadrangles, Contra Costa, Marin, Napa, Solano, and Sonoma

Counties, California: U.S. Geol. Survey Misc. Field Studies map MF-595, scale 1:62,500 [BDC

67]. M(200)4 vUn3mf no.595 stack 35; (200) Un3sfbd no.67

stack 4 and CA Center

MF643 — Sorg, D.H., and McLaughlin, R.J., 1975, Geologic map of the Sargent-Berrocal fault zone

between Los Gatos and Los Altos Hills, Santa Clara County, California U.S. Geol. Survey Misc.

Field Studies Map MF-643, scale 1:24,000. M(200)4 vUn3mf no.643

stack 35

MF677 — Wright, R.H., and Reid, G.O., 1975, Photointerpretlve map of landslides and surficial deposits

of northernmost Napa County, California: U.S. Geol. Survey Misc. Field Studies Map MF-677,

scale 1:24,000. M(200)4 vUn3mf no.677 stack 35

MF719 — Sims, J.D., and Frizzell, V.A., 1976, Preliminary photointerpretation map of landslides and other

surficial deposits of the Mount Vaca, Vacaville, and parts of Courtland, Davis, Lake Berryessa,

and Woodland 15-minute quadrangles, Napa and Solano Counties, California: U.S. Geol.

Survey Misc. Field Studies Map MF-719, scale 1:62.500. M(200)4 vUn3mf no.719

stack 35

MF1406 — Ellen, Stephen, Peterson, D.M., and Reid, G.O., 1982, Map showing areas susceptible to

different hazards from shallow landsliding, Marin County and adjacent parts of Sonoma

County, California: U.S. Geol. Survey Misc. Field Studies Map MF-1406, 8 p., map scale