The first reference I have to the California Motor Company appeared in the motorcycling press in October 1901 . It's brief enough that we can reproduce it here in full:
I haven't had a chance to search for company records, but it's a fair bet the company itself was formed some time around September 1901. Marks filed the first of two patent applications covering the details of his motorcycle on September 7, 1901, and significantly Louis H. Bill was one of the witnesses on the application. (Note the spelling difference: the patent being more "official", I favour "Louis" as the correct version.) No doubt the new company was keen to protect its intellectual property. In a slightly later piece , Leavitt & Bill ("...well known cycle dealers...") were said to be the principal owners of stock in the company, and L. H. Bill was described as "...formerly with the Thomas company". The company premises were listed at 2212 Folsom St., San Francisco.
From the timing of this announcement, we see that if production of California "motocycles" (this spelling was widespread in the early days of the U.S. industry) did begin in 1901, it was very late in the year. By early 1902 the California publicity machine was in full swing and a number of articles appeared in the motorcycling press [2-4]. The first illustration I have appeared in The Motor Age early in February 1902 , corresponding with the release of the first California catalogue. By this time, the company was said to be "...making deliveries".
The machine as shown at this early date is very much as outlined in Mark's patent applications, and differs most notable from later production Californias in that the front fork is rigid, and the drive is by round - rather than flat - belt. Accessories include the Duck brake, and a Garford spring saddle. I'm not sure when the sprung front fork appeared, but a very original early survivor in the US  is fitted with the unbraced fork, but with the sprung rocking links. Advertising through 1903 [6-8] used a photograph showing the braced fork. Strangely little was said about the spring fork in period advertising, especially since in the 1906 Yale-California catalogue the makers claimed: "We were the first to use the spring front fork on a motor cycle".
An amusing omission from this photo is the glass lubricating cup, that sat on top of the crank case. Perhaps it was too embarrassing to admit to!
A significant event in 1902 was the granting on September 30 of two US patents: 710,329 Explosive Engine for Motor-Vehicles (filed September 7,1901), and 710,330 Carbureter for Explosive-Engines (filed January 2, 1902). Although granted to Roy Marks, it seems likely that these patents were "company assets" which protected - and gave value to - their successful product.
1903 was a landmark year for the California Motor Company. It was the year that they "made it" in the motorcycling world, but also the year that they ceased motorcycle manufacture for good.
Undoubtedly the biggest event of the year for the company was George Wyman's success in crossing the continent on his California motorcycle. The publicity generated by this event was huge: not only did it consume pages of the specialist press (for example The Motorcycle Magazine and The Bicycling World and Motocycle Review both carried extensive reports over several issues), but the event captured good coverage in newspapers of the day. California advertising made much of the epic achievement, but perhaps more importantly much of the post-ride editorial comment read like California advertising copy. In these pioneering days of motorcycling, the California was was in the spotlight.
But the directors of the company did not spend too much time basking in the glory. Wyman completed his journey in July, and within three months a deal had been struck to sell the manufacturing rights of the motorcycle to the newly-formed Consolidated Manufacturing Company based in Toledo, Ohio. The details were outlined in an article in the October 17, 1903 edition of The Bicycling World and Motocycle Review headed "KIRK AND SNELL UNITE: Long Allied They Become One Company and Engage in Big Deal in Motor Bicycles". In part the article reads:
The new motorcycle was to be called the Yale-California, and while the first models were very similar to the original California, the machine evolved to become the once-famous Yale.
I'm not sure how much of the California Motor Company lived on in San Francisco after October 1903. Certainly L. H. Bill maintained a profile in the press, but when talking up Yale-California motorcycles in June 1904  his association was given as "C. E. & B. I. Bill", and a testimonial in the 1906 Yale-California catalogue was addressed to "Messrs. Leavitt & Bill". Perhaps someone with access to early San Francisco trade directories can help out?
Another puzzle: in one 1903 advertisement , the address of the California Motor Company is given as 305 Larkin St, San Francisco. The same address is given in January 1902  for The California Handle Bar Company, manufacturers of a rather novel adjustable handle bar. Presumably another of Mr Bill's cycle-based interests. Were Larkin and Folsom Streets nearby? Do the factories still exist?
So there we have it. In two hectic years the California Motor Company was founded, built a motorcycle and a reputation, and then sold out. If the history books are anything to go by, the company has essentially been forgotten, despite producing what should be one of the most famous motorcycles of all time: Wyman's trans-continental mount. Hopefully the 2003 centenary of Wynan's ride will jog some memories.
Thanks to Howard Heilman, Yale enthusiast extraordinaire, how helped out with many of the original references cited here. Other references were found during a fascinating day spent in the reading room at the Library of Congress, Washington DC.