In the Sonoma County Marriages 1847-1902, there is a listing for an Francis D. TROSPER marrying a Marnella J. ADAMS on 24 Sep 1893 in Petaluma by W. H. Darden recorded in Book A Page 86.

Francis Drake Trosper built and operated a resort in Cazadero, California known as the Trosper House. He was also a good friend of Dr. Bruce Cockrill who visited Cazadero and the Trosper family often.

Gary Rodgers, one of the inheritors of this property, and the webmaster of The Cazadero, California Website, has emailed me several items about the resort, along with stories and information about the Trospers and associated families.

From History of Sonoma County California with Biographical Sketches of the leading men and women of the County, by Tom Gregory (Historic Record Company, Los Angeles: 1911), biography of "Thomas Gilbert Woolsey Trosper," pp. 636-637:

FRANCIS DRAKE TROSPER

There is no name better known in the western part of Sonoma county than that of Trosper, of which family the gentleman whose name heads this article is a member and is one of the rising young men and native son of the county. F. D. Trosper was born near Occidental on the Dutch Bill creek, in 1866. His father, Thomas Trosper, the pioneer, is represented with a sketch on another page in this volume. The second youngest of a family of five children, F. D. Trosper was reared on the ranch in the vicinity of Cazadero, receiving his education in the public schools of that locality. Having been reared on his father's ranch and early learning the stock business, after he had reached his maturity he naturally turned to that occupation and at the age of eighteen leased a ranch near Cazadero for five years and gave his attention to stock raising and ranching.

Mr. Trosper was married at Cazadero to Miss Maruella Adams, a native of Ontario, Canada, and who came with her mother, Mrs. Zerviah Z. Adams, to Cazadero when she was eleven years old. After completing her education she taught music until her marriage. After their marriage the young couple located on the Adams place near Cazadero, where Mr. Trosper carried on dairying and farming for five years, after which time he located on his present place and, since 1898, has conducted a summer resort. The Trosper house is situated in the mountains on West Austin creek, two miles north of Cazadero, where he owns two hundred acres. For the pleasure of his guests who enjoy swimming he built a dam across the creek to deepen the water. This creek affords excellent trout fishing and the vicinity furnishes good hunting. The entire place is studded with redwood and pines and is considered a very fine resort. It is conducted the year round and Mr. and Mrs. Trosper are good entertainers and furnish their guests with music, books and both indoor and outdoor amusements, and not only do the grown people find great pleasure and enjoyment, but it is especially attractive to young people and children on account of the freedom and the many outdoor pleasures.

Besides his resort Mr. Trosper is extensively engaged in the raising of Hereford and Durham cattle and also Poland-China hogs and leases the old Hassett ranch of thirty-three hundred acres for the purpose. Mr. Trosper is a Democrat in politics and active in the councils of his party. He was elected justice of the peace of Ocean township in 1888 and has served continuously since that date. Judge Trosper is a man of fine physique and affable manner, making an ideal host. A staunch believer in education, he gives liberally of time, influence and mans for the maintenance of the schools, besides which he is interested in other worthy movements. He is especially interested in the introduction into the vicinity of high-grade stock and by his own efforts in this direction gives an impetus to the stock industry. Judge Trosper has been one of the most active politicians of his party in Sonoma county and by his personality has won and maintained a host of friends.

From Gary Rodgers:

Francis Drake Trosper died 24 April 1923 in his Trosper House bedroom. He had a heart condition and contracted the measles from one of his guests. This aggravated his heart condition and he died of a coronary.

A monument dedicated to Francis Drake Trosper exists about a half a mile north of Cazadero at the intersection of Fort Ross and King Ridge Roads. According to Gary, it was built by Drake's hunting lodge charter members:

California State Senator Herbert W. Slater gave the oratory. The lodge was located on Pepperwood Creek about 10 miles north of the Trosper house. George Larson, a member and jeweler in San Francisco, sculpted the bronze.plaque, and it was dedicated on May 3, 1924. George's wife, Alice, was a niece of Hetty Green, the richest woman in the world and known as the "Witch of Wall Street." (http://www.hettygreen.com/).