Marconi Conference Center
State Historic Park
The mission of California State Parks is
to provide for the health, inspiration and
education of the people of California by helping
to preserve the state’s extraordinary biological
diversity, protecting its most valued natural and
cultural resources, and creating opportunities
for high-quality outdoor recreation.
History and nature
blend seamlessly at the
Marconi Conference Center
State Historic Park, where
native Coast Miwok,
global radio communication,
California State Parks supports equal access.
Prior to arrival, visitors with disabilities who
need assistance should contact the park
at (415) 663-9020. This publication can be
made available in alternate formats. Contact
email@example.com or call (916) 654-2249.
CALIFORNIA STATE PARKS
P.O. Box 942896
Sacramento, CA 94296-0001
For information call: (800) 777-0369
(916) 653-6995, outside the U.S.
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Marconi Conference Center
State Historic Park
18500 State Highway One
Marshall, CA 94940
© 2014 California State Parks
and a controversial cult
have each left their mark.
his bayside retreat in northern Marin
County has a rich and controversial history.
Originally occupied by Coast Miwok people, the
site was then chosen as part of a history-making
global communication chain. Seven of Marconi
Conference Center State Historic Park’s 62 acres
have been designated a historic district, listed
on the National Register of Historic Places.
The site later became world headquarters to
a renowned cult, best known for its tough-love
drug rehabilitation and an attempted murder.
Today, it is a popular conference center and
The park enjoys a Mediterranean climate:
pleasant springtimes and autumns followed by
cool, wet winters. Low-lying fog and offshore
breezes from the northwest moderate the
The indigenous Coast Miwok lived in the area
of Tomales Bay for thousands of years before
Europeans arrived. When English explorer
Francis Drake landed on the Marin peninsula
in 1579, the chaplain of his Golden Hind
galleon noted the friendliness of the native
people in his diary.
The Miwok’s second European encounter
came in 1595. Captain Sebastian Cermeño’s
Manila galleon, the San Agustin, sank in what
is now called Drake’s Bay with a cargo of Ming
Dynasty porcelain. The wreckage is thought
to be buried beneath the bay. The local Coast
Miwok retrieved and used pieces of the Ming
porcelain for tools and ornaments; shards of it
wash up on the beach to this day.
A Coast Miwok tribal village stood about
two miles south of today’s town of Marshall,
near the conference center. The village was
called etkako’lum in the Miwok dialect of the
Penutian language family. Historians estimate
more than 3,000 Coast Miwok lived in Marin
and Sonoma villages.
In 1817, Franciscan missionaries claimed
the Marin peninsula and built Mission San
Rafael, converting native people
to their religion and using them
as a labor force. Most Coast
Miwok people died from
contagious diseases that spread
quickly in the missions’ close
living conditions .
After the missions were
secularized (released from
religious influence) in 1834,
Mexican Governor José Figueroa
Coast Miwok tule boat, 1815
Courtesy of The Bancroft Library
promised to the surviving Miwok an 80,000acre land grant at Nicasio — from Tomales Bay
to today’s San Geronimo. Meant as reparation
for the loss of their tribal lands, this property
was never formally deeded to the
After years of delay, General Mariano Vallejo
granted this land to five Miwok members
on October 14, 1844. The next day, Vallejo’s
nephew, former California governor Juan
Bautista Alvarado, “bought” the land grant
from these Miwok owners. The Miwok signed
a deed in return for Vallejo’s promise to pay
them $1,000. The Miwok never received their
money, nor did they know that two months
before, then-Governor Manuel Micheltorena
had legally granted most of this promised land
to two other people.
Rocky, steep, undesirable land at Graton in
Sonoma County was eventually given to the
Miwok, but some surviving tribe members
chose to labor for others at Nicasio. Others
lived in nearby houses built on pilings over
Tomales Bay, selling harvested shellfish to
make ends meet.
Coast Miwok and some Southern Pomo
formed the Federated Coast Miwok in 1992.
This blended tribe’s federal recognition was
officially restored as the Federated Indians of
Graton Rancheria in 2000. Today’s members,
all descended from the original tribes, honor
the homeland of their ancestors and work to
revive the Miwok language and customs for
Gu gl ielmo Marcon i
(1874 - 1937)
In 1896, at age 22, Guglielmo Marconi received
the first radio patent on his wireless system, using
electromagnetic waves to transmit telegraphic
messages. Building upon prior discoveries by
Heinrich Hertz, Nikola Tesla, Thomas Edison and
others, this young Italian demonstrated that coded
signal telegraphy could be conducted without
wires running from transmitter to receiver.
Marconi’s youthful experiments began at his
childhood home in Bologna, Italy. He expanded
upon Hertz’s and Tesla’s apparatuses, transmitting
radio signals (called Hertz waves at the time) at
increasing lengths. Marconi persisted until he
had significantly raised radio signal-transmission
distances. Propounded in 1897, Marconi’s Law
held that the maximum signal distance between
sending and receiving antennas of equal height is
proportional to the square of the antennas’ height,
using a constant minimum value of current
(i.e., Height = Constant x √Distance). Unlike the
radio-wave pioneers who preceded Marconi,
he put their theories into practice with regular
commercial operation, ultimately achieving his
goal of transoceanic communication.
Proving that the earth’s curvature would
not interfere, he was able to transmit the first
transatlantic radio signals for a distance of
2,100 miles from Cornwall, England, to St. John’s,
Newfoundland, in 1901. Marconi shared the 1909
Nobel Prize for Physics with Karl Ferdinand Braun
“in recognition for their contributions to the
development of wireless telegraphy.”
Despite his important individual contributions
that built on the work of others,
Guglielmo Marconi and his
companies were sued
throughout his career.
The Court of Claims
wireless patents in
1935; on appeal, the
U.S. Supreme Court
overturned them in
1943, long after his
death in 1937. The court’s
decision singled out the
work of Nikola Tesla,
granted in 1900.
Messages ARound the World
Long-wave wireless radio required two “duplex” sending and receiving
stations to be built miles apart because the long-wave wireless static
noise of 300-kilowatt transmission interfered with clear reception.
The Marconi Wireless Company moved Station KPH, a high-powered
wireless transmitting station, from San Francisco’s Palace Hotel to land
near Bolinas. In 1912, the company purchased 1,114 acres near Marshall
from dairy farmer E.G. Maggetti for the signal-receiving station site.
The two sites joined four other U.S. duplex receiving and transmitting
stations — located in Massachusetts, New York, New Jersey, and the
island of Oahu in the Hawaiian Territory. Together, the stations created
the first dependable communication link between ships at sea, the
Continental United States, Hawaii and Japan.
Receiving station KPH, ca. 1920s
The company hired J.G. White, a New York engineering company, to
design and construct the five historic structures at the Marshall receiving
station in 1913 and 1914. The original complex had a luxurious 35-room
residence for staff and families, two cottages for the chief engineer and
the assistant, an operations building, and a powerhouse for electric
transformers and batteries. The three-story residence (now closed), the
one-story Pinecrest and Bayview cottages, and the powerhouse overlook
Tomales Bay from their knoll. The operations building — built far from the
other original buildings — housed wireless receiving
and printout equipment and offices.
On the ridges above receiving Station
KPH, seven 270-foot steel towers set in
concrete supported a mile of single wire
acting as a radio antenna.
Marconi realized his dream of a “wireless girdle ‘round the earth”
with his radiotelegraph system. Radio telegraphy gained credibility
after the 1912 rescue of more than 700 RMS Titanic passengers.
The Great War (World War I) broke out in Europe in 1914, and
control of similar duplex wireless stations in Ireland, Wales and
Russia was seized by their respective countries’ governments. As
the only company capable of transatlantic radio and telegraph
communications, Marconi Wireless Company’s wireless stations in the
United States were all confiscated by the U.S. Navy in 1917. After the
war, keeping such equipment in American hands became a priority.
Because Marconi Wireless Telegraph Company of America was owned
by a British parent company, U.S. naval officials urged General
Electric Company (GE) to acquire the American Marconi Company’s
In 1919, GE formed the Radio Corporation of America (RCA);
that corporation’s bylaws specified that all of RCA’s directors and
officers must be U.S. citizens. RCA then merged with American
Marconi, so the duplex stations at Marshall and Bolinas became
RCA sold all but these 62.4 acres at Marshall in 1922. A new
short-wave receiving station was built at Point Reyes in 1929, yet
Station KPH continued to operate here at Tomales until the start of
World War II. RCA sold the remaining acreage in 1947; eventually,
the Marshall site was sold for $175,000 to the Synanon Foundation
The Marshall site became the world
headquarters for Synanon, which had
originated in Southern California
as a rehabilitation program for drug addicts
in 1958. The term Synanon was accidentally
coined by an addict mispronouncing the
words “seminar” and “symposium.” The
Synanon’s founder, reformed alcoholic
Charles Dederich, had been living on
unemployment checks when he developed
a following of self-proclaimed “dope fiends,”
who were not welcome in alcohol-recovery
programs. At first, Dederich took addicts who
were trying to get clean into his Santa Monica
apartment, scrounging food from grocery
stores to feed them.
As Dederich’s following grew, donations
poured in; the group started purchasing
property throughout the U.S. Working
residents signed their paychecks over to the
“nonprofit” group. Synanon Industries was
launched, operating businesses from gas
stations to repair shops to promotional item
sales — earning about $10 million annually at
Synanon’s initial publicity promised
addicts a lifelong cure from drug dependence
after completing a two-year residential
program. The core of their rehabilitation
process was the “Synanon Game,” a fiercely
confrontational group therapy that developed
after Dederich had ridiculed a gathering of his
loyal followers. In the Game, about a dozen
members humiliated and picked on one
another in turn, with brutal honesty and selfrevelation as the Game’s sole reward.
Synanon’s public meetings generated more
publicity. Attendees came from all social
classes and professions — including a brigade
of lawyers — who donated time, goods and
funds to Synanon. Many were not addicts,
merely “squares” (non-Synanon members)
and celebrities curious about the communal
lifestyle and the Synanon Game.
An estimated 6,000 to 10,000 people passed
through Synanon’s program. After most of its
residency graduates returned to substance
abuse, Synanon declared itself an “alternative
lifestyle community” in 1968, admitting to
cult status and requiring devotees to remain
with Synanon for life. Dederich had members
shave their heads; he chose their partners
and even dictated their reproductive rights.
Between 1964 and 1980, Synanon members
constructed the residences, warehouse,
a geodesic dome, medical clinic, gym,
firehouse, airstrip and dump at the Marshall
site. When authorities tried to enforce
ignored building-permit and taxation laws,
Synanon amended its incorporation status
to become tax-exempt as the Church of
Synanon. At its 1975 peak, the Church claimed
1,700 members worldwide.
A local Marin newspaper, The Point Reyes
Light, started a 1978 investigative series
focusing on children who had run away
from Synanon. A Marin County grand jury
probe found that Synanon had transformed
from a narcotics-treatment program to a
Synanon-era top-floor door
discovery process led to Synanon’s downfall
after prosecutors found Dederich’s taped
recordings ordering brutal beatings and an
On October 10, 1978, two members
removed the warning rattles from a 4.5-foot
rattlesnake and placed it in an opposing
attorney’s mailbox. Paramedics saved the
bitten man’s life, but Dederich (found drunk
in Arizona) and two accomplices were all
convicted of conspiracy to commit murder. In
1978 the court ordered Dederich to abdicate
his role as Synanon’s head.
The Point Reyes Light won a 1979 Pulitzer
Prize for its role in exposing Synanon. The
Church of Synanon collapsed and disbanded;
Synanon properties were either sold or
seized by the government. Some former
members opened their own “tough-love”
A Bay Area philanthropic organization,
the San Francisco Foundation, bought the
Marshall property in 1980; four years later,
they deeded it to the California State Parks
Foundation. The Foundation transferred the
land to the State in 1989, for use as a retreat
and conference center.
The Marconi Conference Center lies on the
north end of Bolinas ridge along the Marin
Peninsula, adjoining Tomales Bay. Some time
after the Pleistocene glacial epoch, the bay was
formed by rising sea waters along the active
San Andreas fault line, which runs through
Tomales Bay to Bolinas. The soils here are
decomposed bedrock: serpentine, shale, chert
The area’s native coastal terrace prairies were
grazed grassland when the Marconi Company
bought the land — ideal for erecting towers to
receive long radio waves.
Today’s vegetation communities are closedcone pine forest, eucalyptus, coastal scrub and
annual grassland. The older Monterey pine trees
were most likely planted after Marconi Company
construction; the eucalyptus and younger pines
were planted in the Synanon era.
Native plants include stands of California bay
and northern coyote brush scrub with California
sagebrush, bush monkeyflower, poison oak,
coffeeberry and toyon.
Birders may see house finches, mourning
doves, wrentits, ravens, California quail,
Brewer’s blackbirds and western
Conference center lobby
bluebirds. Red-tailed hawks
circle above the ridge;
nocturnal strollers may spot a
great horned owl out hunting.
Migratory waterfowl and
shorebirds include great blue
herons and great egrets along
Tomales Bay. The California clapper
rail, a federally endangered species,
has been seen along the bay’s
Common local animals include the blacktailed jackrabbit, brush rabbit, mule deer,
California vole, pocket gopher, gray fox and
western fence lizard.
The idyllic hillside grounds make an ideal
site for retreats and conferences. View details
of lodging, meeting and event spaces, and
meals on the park website at
www.parks.ca.gov/marconi; make conference
or meeting arrangements by calling
(415) 663-9020. Paved and unpaved hiking
trails wend through the tranquil setting.
Please stay on marked trails and be alert for
ticks or poison oak.
In late April of each year, Guglielmo Marconi’s
April 25 birthday is commemorated at historic
Marconi wireless sites around the world.
Volunteers from amateur radio station K6KPH,
the Maritime Radio Historical Society, celebrate
International Marconi Day at both the sending
site in Bolinas and the receiving station here
at Marshall in the original station manager’s
cottage, McCargo Hall. Vintage transmitting and
receiving equipment is used and displayed.
For Marconi Day details, please visit
The park sits on a steep hillside that may
challenge some wheelchair users. Some guest
rooms, parking, restrooms and the conference
halls are accessible, as is the dining hall. Discuss
your needs when calling Marconi Conference
Center for reservations at (415) 663-9020.
• All natural and cultural features are protected
by law and may not be disturbed or removed.
• All animals must be leashed. Except for
service animals, no pets are allowed inside
the buildings or on grounds overnight. Dogs
on leash are allowed on trails during the
daytime. Please pick up after your dog.
• Observe fire safety precautions. Smoking,
cooking, and burning candles or incense are
not allowed in guest rooms.
• Open fires, barbecues and group picnics are
not allowed on park grounds.
• The park has no access to Tomales Bay.
NEARBY STATE PARKS
• Tomales Bay State Park
1208 Pierce Point Road
• Samuel P. Taylor State Park
8889 Sir Francis Drake Blvd.
• Mount Tamalpais State Park
801 Panoramic Highway
Mill Valley 94941
Marconi Conference Center
State Historic Park
Towe r Hi l
to Bodega Bay
Tr a i
S TAT E H I S T O R I C PA R K
Accessible Pedestrian Path
© 2014 California State Parks