Terra Cotta, California
Coal, along with clay deposits, was found on the site by John D. Huff in the late 1880s, and the Southern California Coal and Clay Company was formed to mine them. The town site of Terra Cotta was laid out and was given a post office on October 26, 1887. In May 1893 its post office was closed and moved to Lake Elsinore. A plant for the manufacture of sewer and water pipes was built using the coal to fire ceramic pipes in the four kilns. The finished product had to be shipped by wagon six miles through Lake Elsinore to the La Laguna rail station at the mouth of Railroad Canyon until 1896 when a spur line was built through Lake Elsinore and Terra Cotta to the new clay deposits in Alberhill. The coal mined was also used locally as fuel for the stamping mill at the Good Hope Mine and was shipped elsewhere in the state.
Dungworth
Load Brook was developed from a farm to a minor industrial site in the late 19th and early 20th centuries. A "pot clay" mine (pot clay – a type of fireclay from the Stannington pot clay bed) was developed to the southwest in the 1850s by William Trickett, a local farmer. Trickett obtained rights to mine pot clay from the landowner, the Duke of Norfolk in 1852 and was mentioned in the Sheffield Trade Directory of 1862 as a clay merchant. William Trickett died in 1890 and the business was continued by his three sons, William, Benjamin and Matthew under the name of B. Trickett & Co.