Since riparian ecosystems are characteristic of surrounding rivers, a map of major California rivers can serve as an ideal baseline for locating riparian habitat. This map clearly shows that riparian ecosystems span the entirety of California with only a few spots having no rivers, mostly in deserts. This map is, however, only a baseline for locating riparian ecosystems. Smaller rivers, streams, and creeks that do not appear on this map are all candidates for riparian habitat depending on how development has transformed the surrounding landscape.

Below is a map of the Los Angeles portion of the Santa Monica Mountains. This map illustrates the complexity and abundance of streams and creeks that flow through the mountain valleys and out to the ocean. It is possible that each of these streams or creeks has its own riparian ecosystem. Some of these waterways are perennial with continuous flow in at least some sections year round. Others are intermittent meaning the streams or creeks dry up for some period during the year.