Distribution Maps of Amphibians in the Sierra Nevada

There are 32 amphibian taxa currently found in the Sierra Nevada region of
California. Thirty of these taxa are native species or subspecies; nine are
frogs and toads and twenty-one are salamanders. The bullfrog (Rana catesbeiana)
is non-native and the tiger salamander (Ambystoma tigrinum) is of unknown
origin and may have been introduced to reservoirs in the Owens Valley as fish
bait. The following range maps for the 32 amphibian taxa was compiled by Mark
Jennings of the California Academy of Sciences, as part of the Sierra Nevada
Ecosystem Project (SNEP). His report on the status of amphibians in the Sierra
Nevada is found in Sierra Nevada Ecosystem Project: Final report to Congress,
volume II, Assessments and scientific basis for management options, pg 921-944.

The 32 amphibian taxa depict the taxa richness for the Sierra Nevada,
California.

The range maps from the report were digitized into Arc Info coverages, using
county boundaries as geographic reference points. The resultant polygons are
estimated to be accurate at a scale of 1:2,000,000. We converted all native
amphibian taxa polygons (including the Owens Valley tiger salamander) to a
grid, with a cell size of 5000 m. All thirty grids were then overlayed to
create a grid depicting taxa richness for the Sierra Nevada region.