The Great Valley Grasslands State Park preserves an example of the native grass habitat in the valley, while oak savanna habitats remain near Visalia. There are areas of wetland and riverside woodland in the north especially on the Sacramento River system including the Nature Conservancy's Cosumnes River Preserve just south of Sacramento, Gray Lodge Wildlife Area, Butte Sink Wildlife Management Area, and other patches in the delta area. Remaining vernal pools include Pixley National Wildlife Refuge between Tulare, California, and Bakersfield and Jepson Prairie Preserve in the delta. There are large blocks of desert scrubland in the southern San Joaquin Valley and in the Carrizo Plain, which is just outside the valley but has a similar landscape.