California Division United Daughters of the Confederacy has been placing government issued grave markers for those veterans who served in the War Between the States buried in California. Some 16,000 names and graves have been identified with hopes of compiling a book, including pictures of the grave markers where possible, death certificates when possible, along with as much details of their military service as possible. This book is still in the working stages by the author.
Thus far, she has identified two WATTS, which I copied for this posting with the information listed below.

C. O. Watts, CSA, b. 1835, d June 2, 1905, buried Oakdale Cemetery, Glendora, Los Angeles County. Grave location: Section F, Block 64, Lot B, Space 5.

Thomas Watts, CSA, Co E TN Cavalry, b. 1844 Russellville, TN, d. 1 Aug 1932 Modesto, buried Modesto Citizen's Cemetery. GAR Between 26 & 27 TR4 Gr2. Wife named Frances born Iowa and a daughter named Bessie born Iowa.

I hope this proves helpful for someone seeking Watts who were early settlers of California.
Judy