Elgaria coerulea palmeri

One of these things is not a stick....

The Sierra Northern Alligator Lizard. One of two species in the Sierra Nevada; only this one has a dark iris. I was walking the Mirror Lake loop when a mule train came through and I stepped to the side of the trail, causing the lizard to stir in the detritus. This is the second time I've seen an alligator lizard in Yosemite. The bright orange belly gets me.

A terrific photo of the species is here, on a Yosemite blog.