Sarah,

For what it is worth, the 1913 Directory of Clay Products Manufacturers in
the United States lists 19 tile manufacturers in California, but none in
Corona or in Riverside Co.  No telling how complete this directory is,
however.

Also, a Corona, Calif., website has the following:

Other more successful mining ventures included the Minnesota Mining and
Manufacturing Company (previously Blue Diamond mine,) the Pacific Clay
Company (organized in 1886,) Redlands Clay Tile, Maruhachi Ceramics, Monier
Roof Tile and U.S. Tile.

The presence of Pacific  Clay and U.S. Tile suggests fairly substantial
enterprises at some point in the town's history.

If you had firmer dates, it would be worthwhile poring through old issues
of Brick and Clay Record and the Clay Worker, as these contain numerous
news notes and articles on clay companies throughout the U.S.

James L. Murphy
Ohio State University Libraries
Columbs, OH 43201
At 02:45 PM 5/22/01 -0700, you wrote:
>On 22 May 01, at 14:26, sarah cowie wrote:
>
> > Hi folks,
> >
> > A colleague of mine has excavated some ceramic roofing
> > tiles (barrel tiles) from two early 20th century sites
> > in Riverside County, California.  Both sites are
> > located near a town known historically as a center for
> > small ceramic industries owned by Mexican-Americans.
> >
> > Excavators found two ceramic kilns and waster tiles at
> > one site, and some tiles have an impressed mark
> > reading "CASA BLANCA CORONA".
> >
> > A large dump/waster pile was excavated at the second
> > site; tiles from that location are impressed marks
> > reading "D.J.C.P.",   "CASA BLANCA CORONA",   and "LA
> > OLLA TILE CORONA".  The latter mark is within a
> > triangle.
> >
> > Does anyone have any information on these marks?
> > Anyone found them at other locations?  Is there any
> > chance of finding a roof tile makers mark guide?
> >
> > Please reply to me off list if you have specific
> > information on these marks.
> >
>
>
>Sarah-