Sailing from San Francisco to Bodega Bay back in 1850, Irish immigrant John Keys ducked into Tomales Bay and turned left after passing a small peninsula now called Tom's Point.

He explored the estuary, later known as Walker Creek, and found a smaller creek, one he believed could be his key to success. That one is now called Keys Creek.

Keys was 17 in 1841 when he left his home in County Fermanagh in the north of Ireland. He emigrated to St. Louis, where an uncle had previously settled.

He moved to San Francisco in 1849, and early the next year, he relocated to Bodega, where he immediately began growing potatoes. However, having seen the rolling hills and navigable creeks south of the Marin-Sonoma border, he knew he wouldn't be in Bodega long.

So, in September of 1850, Keys became one of the first non-native residents of Tomales Township, and until 1857, he and his schooner Spray transported passengers, livestock, lumber, and potatoes between Bodega, Tomales, and San Francisco bays.

Keys was typical of the first Irish immigrants to West Marin: he left a desperate existence in the Emerald Isle, sailed virtually penniless to an uncertain future in America, toiled in the East until hearing California was littered with gold, and - chasing this fantasy - found his way to Tomales.

"A lot of them went to the gold fields first but didn't make their millions, so they soon found they had to look elsewhere for a living," noted Tomales historian Lois Parks.

"They came in and made money and sent for family members, and they settled here," she said. "They certainly were strong. They came a long way from home and left everything to start anew. And they succeeded."

Roughly 117,000 men, women, and children escaped Ireland's misery in 1847, known as "Black '47" and widely regarded as the worst year of the Great Hunger.

That was the year brothers Hugh, Samuel, James, David, and Alexander Marshall emigrated from their home in County Armagh, northern Ireland, leaving behind their three oldest brothers, William, Robert, and Joseph.

Unsatisfied with the brothers' newfound home in Philadelphia, Hugh Marshall trekked across the country in 1852 and wound up in Tomales, where he settled on a ranch now owned by sheep rancher Gordon Thornton, a Marshall-family descendent and current president of the Marin County Farm Bureau.

Meanwhile, Samuel, James, David, and Alex Marshall gave Louisville, Kentucky, a try. But it wasn't long before Hugh, a Presbyterian minister, wrote his younger brothers and persuaded them to join him in West Marin.

In 1853, Samuel, James, and David drove a large herd of cattle west to Tomales. They returned to Louisville the following year to fetch more cattle, along with their brother Alex and his new bride Fannie. In 1854, Alex and Fannie went to work for John Keys, and she gave birth to Emma Jane Marshall, the first non-Indian child born in Tomales Township.

Hugh Marshall eventually moved north. His brother David died at the age of 28. But brothers Samuel and James Marshall prospered in West Marin, buying up extensive acreage on the east shore of Tomales Bay. They built the Marshall Hotel and wharf, and in the process, gave the town of Marshalls its name. (The final "s" in the name was eventually dropped.)

The family's success continued well into the 20th Century. A descendent, James A. Marshall, served as county supervisor from 1955 to 1959 and as Farm Bureau president in 1965 and 1966.

He was not the only Irishman to be a county supervisor. Hardly. Belfast-born Henry Goudy, grandfather of Tomales rancher Glenn Parks, held the seat from 1901 to 1916. Tomales dairyman William Rowland, who left the north of Ireland as a young child, served from 1876 to 1879. And immigrant Peter Morrisy from County Cork also represented West Marin. And dairyman Jim Kehoe, an immigrant's son, served from 1941 to 1956.

Like Marshall, the tiny village of Fallon just north of Tomales also got its name from an Irish immigrant.

James Fallon was no more than 16 when he became the man of the family. He, his mother, and his six younger brothers and sisters left an ailing father in County Roscommon before the terrible potato blight. The Fallons landed in Boston and made their home there.

But in 1849, Luke Fallon, 16 and restless, was lured to California by the Gold Rush. He sailed from Boston around Cape Horn into San Francisco Bay and immediately went to work in the gold fields.

Four years later Luke Fallon took the money he earned, went back to San Francisco, married an Irish immigrant named Mary Coyle, and decided to become a potato farmer in West Marin.

By then, his older brother James had joined him in San Francisco. But while Luke and Mary and their infant son Thomas began their new life as farmers, James did what Luke had done; he went to the gold fields. After six years of prospecting, James again followed his little brother's footsteps, returning to San Francisco, marrying an Irish immigrant - Delia Dunning - and heading north to West Marin.

James and Delia Fallon first settled in the area between Estero de Americano and present-day Dillon Beach. James later bought property adjacent to his brother's in a valley located a couple miles north of Tomales Township. At the time, that area was merely farmland informally known as Griffin's Valley.

John Griffin too was an Irish immigrant. At 17, he had escaped Ireland's County Limerick during Black '47. Griffin prospected in Mariposa County for a time before settling in Tomales.

Unfortunately for Griffin, his chance at immortality was swept away when the narrow-gauge railroad was built up the coast in the mid-1870s.

Since Luke Fallon was generous enough to allow a right of way through his property for the tracks, a grateful railroad officially called the Griffin Valley whistlestop "Fallon," thus forever memorializing the Fallons at the expense of the Griffins.

At the time, Fallon had a creamery - built in 1871 by Luke Fallon - a postoffice, and a grocery store, amenities which made Fallon much more of a village than it is today.

Fittingly, the creamery site, though no longer a creamery, is still in Irish hands. These days, it serves as rancher Bill McCall's basement. McCall's late father Alex was an immigrant, as were his maternal grandparents, the McDowells.

Another Irish immigrant who managed to memorialize his family in a town name was George Dillon, who settled in West Marin in 1856. In those days, the sandy coastline now known as Dillon Beach was merely the west end of somebody's dairy ranch.

Dillon, his brothers Jerome and William, and sister Catherine had left their parents in Ireland in 1846.

Settling in Tennessee, George Dillon moved first to Missouri, where he met his future bride Matilda. The couple then crossed the Great Plains, the Rockies, and Sierra, arriving in Tomales a decade after Dillon left Ireland.

Within three years of settling in West Marin, Dillon acquired 644 acres of the beachfront property that now bears his name and later added another 262 acres.

The property came to be known informally as Dillon's Beach when Dillon began allowing friends and neighbors to picnic on the sand. In 1888, he opened an 11-room hotel, grocery store, and postoffice - the complex now called Lawsons' Resort.

The town got its official name in 1903, when Dillon sold the ranch to John Keegan of Santa Rosa on the condition that the strand forever bear his name.

The next owner, the San Francisco-based California Eucalyptus Plantation Company, in 1922 leased the property to Sylvester Lawson from Woodland, Yolo County. The Lawsons began buying portions of Dillon's Beach in 1937.

Although oldtimers in Tomales and Dillon Beach still refer to the resort town as Dillon's Beach (or merely "Dillon's") the US Postal Service long ago dropped the possessive "s."