īecause the San Jacinto basin is actively and rapidly subsiding (on a geologic time-scale), the USGS estimates that the potential size of the lake (the rapidly expanding closed depression) will continue to grow. If dry conditions persist, experts speculate that it will dry up altogether, becoming an ephemeral lake. In recent years, the lake has decreased from thousands of acres to under 200 acres (0.81 km 2). The lake lies within the outlet area of the San Jacinto River and is typically full only during late winter and spring when the river is flowing.
The lake persists from one year to the next, and at other times it completely dissipates during the dry season. Description Mystic Lake receding during dry times. The town of Lakeview received its name for its proximity to Mystic Lake. The lake is located east of the Lake Perris reservoir and the town of Lakeview, between the cities of Moreno Valley, to the north, and San Jacinto, to the south. The Mystic Lake area attracts one of the most diverse populations of birds in the United States, with over 200 species identified.
The lake's size can vary widely each year. Mystic Lake is a seasonal lake in the San Jacinto Valley of western Riverside County, California.
