1.

  1. All scales smooth, flat, rounded posteriorly .....Western Skink, Plestiodon skiltonianus
  2. Scales either granular, keeled, or pointed .....2

2.

  1. Longitudinal skin fold on each side of body .....3
  2. No longitudinal skin folds on sides .....4

3.

  1. Dark stripes along edges of belly scales .....Northern Alligator Lizard, Elgaria coerulea
  2. Dark stripes on center of belly scales .....Southern Alligator Lizard, Elgaria multicarinata

4.

  1. Spiny ridges or spines at rear of head .....Pygmy Short-horned Lizard, Phrynosoma douglasii
  2. No ridges or spines at rear of head .....5

5.

  1. Gular fold with granules .....Common Side-blotched Lizard, Uta stansburiana
  2. No gular fold with granules .....6

6.

  1. Scales on rear of thigh granular (not overlapping); throat with mottled blue patches .....Sagebrush Lizard, Sceloporus graciosus
  2. Scales on rear of thigh imbricated (overlappping); throat with solid blue patches .....Western Fence Lizard, Sceloporus occidentalis

Adapted by Dennis Paulson from key in Nussbaum,R. A., E. D. Brodie, Jr., and R. M. Storm. 1983. Amphibians & Reptiles of the Pacific Northwest. Univ. Press of Idaho, Moscow. Names revised December 2013.