By Adam Clark, YCC group leader, July 2008 at Phoenix Zoo for Conservation trip with YCC staff

During an early July, 2008, visit to several mine complexes in the Agua Dulce Mountains, refuge staff reported a small banded rattlesnake that fit the description of a tiger rattlesnake (Crotalis tigris).  According to published range maps, the Agua Dulce Mountains contain the westernmost tiger rattlesnake records within the U.S..  In an attempt to verify the reported sighting, we revisited the mine complexes July 20, 2008.  Upon reaching the site, two small banded rattlesnakes were quickly discovered within the adits along with two black-tailed rattlesnakes.  The banded rattlesnakes were identified as speckled rattlesnakes (Crotalis mitchellii).  Both snakes were small adults, less than 30 inches in total length and both had banded pattern, diffuse anteriorly becoming distinct posteriorly including a short series of dark bands adjacent to the rattle.  Tiger rattlesnakes differ by having distinct banding throughout and a lack of distinctly dark bands adjacent to the rattle.