Altitude and location are everything when it comes to biodiversity in this region of California.

In the lower foothills, north-facing slopes in river canyons are dark green and dense with vegetation such as Douglas fir, ponderosa pine, and maple. South facing slopes, in contrast, are more desert-like, with grassy slopes, bull pine and chaparrel.

Are you a person who loves maps of all kinds? Then this site, from the California Environmental Resources System (CERES) is for you. Look at Sierra region maps that show vegetation, topography, land ownership and more.

And here's more, from a page designed for South Yuba River State Park. However, many of the photos described and photographed here occur throughout the Sierra Nevada foothills.

Learn, too, from the Sierra College Museum of Natural History.

The non-profit Central Sierra Environmental Resource Center (CSERC) works on environmental issues in the central Sierra Nevadas. The organization can be reached at cserc@sonnet.com, P. O. Box 396, Twain Harte CA 95383; (209) 586-7440.

And then there's the Sierra Foothill Conservancy, established in 1996. Its goal is to preserve crucial lands in the foothills of Fresno, Madera and Mariposa counties.

The Sierra Nevada Alliance is a loose-knit organization consisting of lots of smaller groups concerned about the future of the Sierra Nevada Mountains. Beautiful, in-depth web site with lots of information.

The American River Conservancy, headquartered in Coloma, conducts conservation, education, and stewardship programs to protect and enhance native fisheries, vanishing plant and animal communities, scenic vistas, cultural heritage and recreational lands within the American and Cosumnes River watersheds which lie in the foothills of the eastern Sacramento Valley.