The Inland Empire has smog on a regular basis. The Santa Ana Mountains are completely obscured.
The Inland Empire also has Santa Ana Winds that lead to clear days, free of smog. The street which "faded" into the smoggy haze is clear, and the Santa Ana Mountains are clearly visible.
At the end of the nineteenth century, the Inland Empire was a major center of agriculture, including citrus, dairy, and winemaking. Agriculture declined in the twentieth century. Since the 1970s a rapidly growing population came in search of affordable housing. This led to more residential, industrial, and commercial development. The area has a population of about four million.[1]