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.
Aldridge
In the 1800s, Aldridge became an industrial town with coal mines and lime kilns. The coal and clay in the area prompted many to set up collieries and brickworks. Aldridge clay is especially useful in the manufacture of blue bricks. The 1881 census shows that the mines and brickworks were major employers. Because the coal and clay beneath the eastern side of Aldridge (towards Stonnall) is located much deeper under the surface, extraction of this coal and clay would not have been economically viable. As a result, farms continued to dominate the eastern part, though a sand quarry was set up and still remains on Birch Lane.