California slender salamanders are a lungless species that has an especially long and slender worm-like body. They have reddish-brown stripes along their backs from head to tail. This stripe fades as the animal ages. Mature adults can grow to five-and-a-half inches in total length.
In Oregon, this salamander usually lives in humid coastal conifer forests. In redwood forests, this salamander easily blends in with bark and other debris. During warm wet weather, California slender salamanders take cover just beneath the surface; if conditions are especially dry, salamanders may retreat deep into crevices, logs, stumps, or insect and worm burrows underground.
As a coastal species, the California slender salamander can tolerant salt better than other amphibians.