Although she was the last member of a family who had held the original Mexican land grant for Bolinas, Rose Briones left little behind in the Dogtown schoolhouse to suggest her family once owned much of West Marin.

Briones, who died in 1983, lived modestly in a one-room schoolhouse near the end of her life, sorting government checks from piles of junk mail and sipping tea among homemade quilts and furniture so antique that it had been delivered to town by schooner.

Yet down in the basement she kept a fire-proof box within an old chest. Inside the box, she stored a thick packet of mortgages, deeds, bills, and legal records that had been burned around the edges but somehow survived the flames.

Among these papers was the last will and testament of her grandfather, Gregorio Briones, the Mexican rancher who in his lifetime owned and lost nearly all of Bolinas.

Now all these documents detailing the rise and fall of the Briones family belong to the Bolinas Museum.

Donated by a Calistoga real estate broker last month, the papers record the affairs of early Bolinas and its first settlers, who made their homes on the Briones' Rancho Baulenes.

Robert Beck, the donor, discovered the papers in the old schoolhouse after he bought it from one of Briones' nephews around the time of her death.

Unmarried and childless, Rose Briones died at age 101 in a San Rafael rest home after living more than 90 years in Dogtown.

Her home remained just as she left it, concealed from motorists on Highway 1 by a grove of trees and thus undisturbed by vandals. Beck said walking into the old schoolhouse for the first time was like stepping back through time.

The Briones family settled in Marin County in 1837, when Rose's father, Pablo, started tending his father's cattle by Bolinas Lagoon. Pablo was 14 years old then, nearly alone in an untamed country where grizzly bears outnumbered men.

Pablo lived with his uncle, Don Rafael Garcia, who owned all the Olema Valley. His mother, Ramona Garcia Briones, joined him the following year, and Gregorio Briones finally arrived at his brother-in-law's ranch in 1839.

Garcia soon moved further north up the Olema Valley, giving the southern portion of his property to the Briones family. Gregorio Briones would then spend the rest of his life fighting authorities for legal ownership of the land or selling it piece by piece at unfavorable terms.

Briones petitioned the Mexican authorities for the title to Rancho Baulenes in 1841, starting with a shoddy survey he conducted with neighboring ranchers.

They sketched out an approximately 13,000-acre ranch that included everything between the end of Duxbury Reef and the foot of Mount Tamalpais, and miles of land northward over the Bolinas Mesa and into the Olema Valley.

Gregorio then sent Pablo to Monterey and Los Angeles to have the grant approved by the Mexican governors. In 1846, two leagues of land were finally given to him, leaving only three peaceful years before his troubles started.

After the Gold Rush, Gregorio Briones found himself consumed by a society he didn't quite understand. His was a world of familial bonds and open friendship, but he was now surrounded by shrewd US businessman and unscrupulous lawyers.

Briones' generous ways no longer served him as well as they had. He would slaughter a bull without hesitation to feed shipwrecked passengers on Bolinas Beach, and he would just as readily sell the east side of Bolinas lagoon for $5 an acre.

A three-year legal battle with the US Land Commission followed by a private claim against his property finally exhausted Briones' wealth. Nearly all of his property was sold to pay his lawyers.

Gregorio Briones' last will and testament, dated May 1, 1863, was a short document. To his wife, he left his modest palizada and a team of oxen. All that remained of his ranch, less than 3,000 acres now, was to be divided equally between his five children, with a small plot left over for a Catholic church. Ten days later Gregorio Briones was dead.

Rancho Baulenes was no more, but the burgeoning towns of Bolinas and Dogtown prospered because of logging nearby redwoods. These whiskey villages brought new people and new ways to the area, and the Briones descendants accepted them as best they could.

Despite considerable the newcomers' prejudice against Mexicans, Pablo Briones became the patron of Dogtown.

Although he worked as a common copper miner and operated a lumber mill, Pablo also held two of the most honored professions of the time. He was a stage coach driver, braving dangerous roads, and a country doctor, whose expertise consisted of folk remedies passed down through generations.

And at a time when Dogtown changed its name to Woodville to attract eligible women, the Briones daughters had no problem finding promising suitors, which was all that was expected of them.

Their father, who never learned English, would have preferred they married Mexicans instead of men like Hiram Nott and Charles Lauff, however.

This second generation of Brioneses left many of the documents found in the Dogtown schoolhouse. Most of the letters are written in Spanish, the family's preferred language, and most of the women seem to have been illiterate, signing legal papers only with a mark, said Chronicle cartoonist Phil Frank, a parttime Bolinas resident and a trustee of Bolinas Museum.

The museum is currently translating most of the documents in preparation of an exhibit that will include pictures or portraits of the signatories, as well as information about their lives and times, he said.

When Rose Briones died she took the last memories of those days with her. Those who used to visit her in that one-room schoolhouse recalled a simple woman who lived with minimal necessities.

The daughter of Pablo Briones had plumbing in her house but lived without running water after her well ran dry. Friends and relatives brought her meals and bottled water, but the only money she ever received apparently came from the government.

Beck said the coarse, wooden schoolhouse that Rose attended as a child still looks as if it belongs to the 19th Century. Its walls, windows, and foundation have survived the passing years, he said, and you can tell the few withered apple trees growing in the backyard once bore fruit.