This species has 2 disjunct ranges. One stretches east from central Arizona into west central New Mexico. The other is in north central Mexico.
This highly aquatic species lives in and around rocky rivers and streams with clear, flowing water. Typically found in desert scrub or conifer forest habitats. It will sometimes drape itself from overhanging branches at the water's edge.
Named for its distinct narrow, elongated head, this snake averages 32-44 inches in length. It has keeled dorsal scales, large plate-like scales on the head, and smooth ventral scales. It is often subtly patterned with alternating rows of round dark spots on a mid-toned background. It has dark vertical bars between the scales around its mouth.
Learn more with Schechter Natural History's Guide to Reptiles and Amphibians