Here's a link to the above act for your reading pleasure. I also link some additional info.

http://www.epw.senate.gov/esa73.pdf

Endangered Species Act - Wikipedia, the free encyclopedia

Species Profile for Giant Garter snake (Thamnophis gigas)

Species Profile for San Francisco Garter snake (Thamnophis sirtalis tetrataenia)

http://www.gpo.gov/fdsys/pkg/FR-2011...2011-12861.pdf

http://www.gpo.gov/fdsys/pkg/FR-2007...504.pdf#page=1